Bazan v. Gonser

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Nebraska Supreme Court Advance Sheets
322 Nebraska Reports
BAZAN v. GONSER
Cite as 322 Neb. 54
Elisban A. Bazan, appellant, v. Eric M. Gonser
and Elite Fleet Hauling, LLC, appellees.
___ N.W.3d ___
Filed August 21, 2026. 	No. S-25-111.
1. Evidence: Appeal and Error. Generally, the control of discovery is a
matter for judicial discretion, and decisions regarding discovery will be
upheld on appeal in the absence of an abuse of discretion.
2. Appeal and Error. Appellate review of a district court’s use of inherent
power is for an abuse of discretion.
3. Judgments: Words and Phrases. An abuse of discretion occurs when a
trial court’s decision is based upon reasons that are untenable or unrea-
sonable or if its action is clearly against justice or conscience, reason,
and evidence.
4. Courts. Nebraska courts, through their inherent judicial power, have
the authority to do all things necessary for the proper administration of
justice.
5. Trial: Expert Witnesses: Appeal and Error. There is no exact stan-
dard for fixing the qualifications of an expert witness, and a trial court
is allowed discretion in determining whether a witness is qualified to
testify as an expert. Unless the court’s finding is clearly erroneous, such
a determination will not be disturbed on appeal.
6. ____: ____: ____. An appellate court reviews de novo whether the trial
court applied the correct legal standards for admitting an expert’s testi-
mony, and it reviews for abuse of discretion how the trial court applied
the appropriate standards in deciding whether to admit or exclude an
expert’s testimony.
7. Trial: Expert Witnesses. Whether a witness is qualified as an expert is
a preliminary question for the trial court.
Appeal from the District Court for Cass County: Michael
A. Smith, Judge. Affirmed.
Nebraska Supreme Court Online Library
www.nebraska.gov/apps-courts-epub/
10/18/2026 12:37 AM CDT

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Nebraska Supreme Court Advance Sheets
322 Nebraska Reports
BAZAN v. GONSER
Cite as 322 Neb. 54
Ross R. Pesek and Daniel C. Martin, of Pesek Law, L.L.C.,
for appellant.
Matthew B. Reilly, Thomas J. Culhane, and Raymond E.
Walden, of Erickson | Sederstrom, P.C., L.L.O., for appellees.
Funke, 	C.J., 	Cassel, 	Stacy, 	Papik, 	Freudenberg,
Bergevin, and Vaughn, JJ.
Papik, J.
After Elisban A. Bazan was injured in a collision with a
commercial vehicle, he sued the other driver and the owner
of the commercial vehicle—Elite Fleet Hauling, LLC (collec-
tively Elite Fleet). Bazan maintained that the accident caused
him to experience a mild traumatic brain injury (mTBI),
also known as a concussion, requiring treatment; Elite Fleet
asserted that Bazan had not experienced an mTBI at all. This
appeal is about the expert witnesses the parties used to sup-
port their positions. The district court did not permit Bazan’s
treating physician to testify as an expert regarding whether
the accident caused Bazan to sustain an mTBI and regarding
related aspects of Bazan’s prima facie case, because Bazan
had not complied with the district court’s progression order.
The district court did, however, allow testimony by Elite
Fleet’s expert, a neuropsychologist, that Bazan did not sustain
an mTBI in the collision, over Bazan’s claims that the wit-
ness was not qualified. Bazan now challenges these rulings on
appeal. Finding no error, we affirm.
I. BACKGROUND
Bazan was driving on Interstate 80 when his vehicle was
struck by one of Elite Fleet’s commercial semi-trucks. Bazan
sued Elite Fleet and alleged that as a result of Elite Fleet’s
negligence, he suffered injuries and was entitled to damages.
Elite Fleet admitted that its negligent acts or omissions proxi-
mately caused the accident, but it denied the causation, nature,
and extent of Bazan’s alleged injuries and his damages.

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BAZAN v. GONSER
Cite as 322 Neb. 54
During the course of the litigation, the district court made
rulings on expert testimony that addressed whether the accident
caused Bazan to suffer an mTBI that necessitated treatment and
resulted in significant damages. After extensive pretrial dis-
covery procedure, the district court found that Bazan had not
adequately disclosed information about Dr. Demetrio Aguila’s
expert testimony and therefore prohibited Dr. Aguila from
testifying for Bazan regarding causation, permanency, and
future medical costs. Had Dr. Aguila testified on these topics,
he would have opined that the accident caused Bazan to sus-
tain an mTBI with symptoms that required regular, long-term
treatment. Dr. Aguila also would have testified about the cost
of that future treatment. The district court allowed Elite Fleet
to present the expert trial testimony of neuropsychologist Dr.
Ryan Ernst that Bazan did not incur an mTBI in the accident,
over Bazan’s assertions that a psychologist is not qualified to
testify as to the “medical diagnoses” of an mTBI. We chron-
icle additional facts pertinent to the district court’s rulings on
expert testimony in more detail in the analysis section below.
In the end, the jury returned a verdict for Bazan in the
amount of $100,000, far below the damages he sought. The
district court entered judgment on the verdict and overruled
Bazan’s motion for new trial, which challenged the district
court’s expert witness rulings.
II. ASSIGNMENTS OF ERROR
Condensed and restated, Bazan assigns on appeal that the
district court erred in (1) excluding the testimony of Dr.
Aguila on the topics of causation, permanency, and future
medical expenses and (2) allowing Dr. Ernst, a “psycholo-
gist,” to render a “medical diagnosis,” outside the scope of his
licensure, by testifying that Bazan did not sustain a traumatic
brain injury.
III. STANDARD OF REVIEW
We recite the applicable standards of review in the sec-
tions below.

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BAZAN v. GONSER
Cite as 322 Neb. 54
IV. ANALYSIS
1. Dr. Aguila
(a) Background
(i) Pretrial Discovery Procedure
In August 2022, the trial court’s first progression order
scheduled trial and directed Bazan to disclose his expert wit-
nesses by a designated date. The progression order required the
disclosure to, among other things, “contain a complete state-
ment of the opinion to be rendered and the basis therefor[].”
The progression order continued, “Expert testimony will not
be permitted at trial unless it is contained in the disclosure.”
During the ensuing months, the district court rescheduled trial
and amended the deadline for expert witness disclosures, but
otherwise, the relevant required content did not change.
Bazan’s disclosures during the months after the initial pro-
gression order indicated he anticipated calling Dr. Aguila to
“testify consistent with his [disclosed] medical records” that
Bazan suffered a traumatic brain injury caused by the acci-
dent and that he needed future medical care as a result. Bazan
disclosed visit notes prepared by Dr. Aguila, which docu-
mented that in 2022, he began treating Bazan for headaches
that arose immediately after the 2020 accident. According
to Dr. Aguila’s visit notes, Bazan reported to Dr. Aguila
that his vehicle was rear-ended by a semi-truck while he
was wearing his seatbelt, that his airbags did not deploy,
and that he lost consciousness. The visit notes also recorded
Dr. Aguila’s impression that an “[a]ssociated diagnos[i]s” of
the traffic accident was “[c]oncussion with loss of conscious-
ness of unspecified duration.” The visit notes reflected that
Dr. Aguila advised Bazan he was a candidate for a procedure
to treat his headaches and that Bazan underwent multiple
rounds of the procedure, after each of which Bazan experi-
enced initial headache relief and then a subsequent return of
the pain. Dr. Aguila noted that he anticipated Bazan would
have the procedure repeated.

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BAZAN v. GONSER
Cite as 322 Neb. 54
Concurrently with these disclosures, Bazan’s counsel wrote
a letter to Elite Fleet’s counsel. The letter stated that Bazan
intended to present evidence related to various injuries and
symptoms, including evidence that he suffered a traumatic
brain injury caused by the accident and that he needed future
medical care as a result. According to the letter, Dr. Aguila
would testify that “Bazan’s medical treatment was caused by
the crash, reasonable, necessary, and reasonably priced.”
In October 2022, Elite Fleet filed a motion in limine asking
the district court to exclude Dr. Aguila as a witness. Elite Fleet
asserted that Bazan had fallen short of the operative progres-
sion order’s requirement that expert witness disclosures shall
“contain a complete statement of the opinion to be rendered
and the basis therefor[].” The district court overruled Elite
Fleet’s motion in limine, without prejudice. But the district
court cautioned Bazan that at that time, his disclosures about
Dr. Aguila’s testimony “[did] not comply with the require-
ments of . . . the Progression Order. The responses must be
more explicit.”
Bazan subsequently supplemented his answers to Elite
Fleet’s discovery requests on December 15, 2022. Bazan’s
counsel 	summarized 	Dr. 	Aguila’s 	qualifications 	and 	the
likely content of Dr. Aguila’s testimony concerning causa-
tion, prognosis, and future medical costs. The supplemental
answers stated that Dr. Aguila would testify consistent with
his medical records, “some of which have been disclosed.”
Specifically, Bazan’s counsel stated that Dr. Aguila would
likely testify about the “broader course of [Bazan’s] treat-
ment dating back to his [emergency room] visit immediately
after the crash and up to present day.” Bazan’s counsel stated
Dr. Aguila would testify that Bazan’s medical treatment was
“caused by the crash, reasonable, necessary, and reasonably
priced”; that the injuries incurred in the crash caused Bazan
significant disruptions to his daily life; that the “injuries suf-
fered are permanent, progressive and painful”; and that the
injuries would require ongoing medical care for the rest of

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BAZAN v. GONSER
Cite as 322 Neb. 54
Bazan’s life. Bazan’s counsel stated that Dr. Aguila would
explain for the jury and generally endorse the findings con-
tained in records produced by a provider to whom Dr. Aguila
referred Bazan as part of a “coordinated treatment plan”
for evaluation regarding “ongoing health complications felt
since the subject crash.” Bazan’s counsel alleged that “the
aforementioned medical opinions . . . will be consistent with
[Bazan’s] written discovery answers or future deposition or
live trial testimony.”
To the December 15, 2022, supplemental answers, Bazan
attached some medical records. They included Dr. Aguila’s
visit note from November 2022 documenting Bazan’s treat-
ment for continued headaches and reiterating past impressions.
They also included a concussion assessment conducted upon
referral by Dr. Aguila. That assessment concluded that Bazan’s
symptoms were “consistent with post-concussion syndrome”
following the collision and required “[s]killed concussion-
based” therapy.
Also in December 2022, Elite Fleet took Dr. Aguila’s depo-
sition. Upon examination by Elite Fleet, Dr. Aguila admitted
that his records did not contain an analysis regarding whether
Bazan’s diagnoses were caused by the collision, an analysis
regarding permanency, or an opinion regarding future treatment
or future costs.
At the December 2022 deposition, Dr. Aguila noted that
Bazan had reported headaches to providers for years starting
immediately after the collision and that Dr. Aguila had person-
ally treated Bazan and ordered objective testing. Based on his
review of all that information, plus his knowledge, training,
and experience, Dr. Aguila opined that Bazan had sustained a
brain injury caused by the collision.
More specifically, when asked what was significant about
Bazan’s medical history that led Dr. Aguila to diagnose a
concussion, Dr. Aguila testified, “[T]he mechanism of injury,
the fact that [Bazan] had headaches, and—you know, and
his report of losing consciousness.” He further testified that

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BAZAN v. GONSER
Cite as 322 Neb. 54
records from the emergency room on the day of the crash
“gave some details about the mechanism of the crash that
. . . helped [him] understand better what was going on, what
had happened to [Bazan] . . . [and] talk[] about him moving
at a pretty high rate of speed.” In a similar vein, Dr. Aguila
identified his “basic understanding” of the “mechanism of
injury”—that Bazan was “involved in a car crash . . . at a
high rate of speed . . . on the interstate.” Dr. Aguila opined
that the findings documented in the emergency room on the
date of the accident were “caused by the crash.” Dr. Aguila
referred to notes from another provider that stated Bazan was
a “restrained driver” traveling at an estimated speed of 70
miles per hour when his vehicle was struck at the rear by a
semi-truck traveling at an estimated 80 miles per hour, that
Bazan’s airbag did not deploy, and that his vehicle went off
the roadway, turning about 180 degrees. Dr. Aguila testified
that he agreed with previous medical records that stated that
injuries suffered by Bazan were a direct result of the collision.
Dr. Aguila also opined that “the most likely explanation” for
evidence of a concussion shown by the objective testing he
ordered “is the trauma that [Bazan] sustained,” because Dr.
Aguila knew that “there was major car crash . . . where he
got run off the road.” Dr. Aguila noted that he had not been
provided with any medical records that showed a preexisting
head injury.
As for Bazan’s prognosis, Dr. Aguila opined at the deposi-
tion that Bazan would suffer “permanent long-term conse-
quences because of this head injury in this crash,” including
an increased risk of dementia and Alzheimer’s disease. He also
testified headaches were a “permanent consequence[] from
this car crash,” agreeing that if Bazan’s condition “returned
to its baseline from before this crash,” Dr. Aguila would
“report that as a temporary aggravation,” and that if Bazan
was “continuing to have ongoing pain and his baseline is not
the same,” it would be Dr. Aguila’s “opinion that it’s a per-
manent aggravation.” According to Dr. Aguila, the procedure

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Nebraska Supreme Court Advance Sheets
322 Nebraska Reports
BAZAN v. GONSER
Cite as 322 Neb. 54
he had used to reduce the intensity of Bazan’s headaches gave
Bazan significant relief in the first round before starting to
wear off, and it “seems as though [Bazan] falls into that cat-
egory of patients who will likely need to have this repeated
in the future.”
On February 8, 2023, the district court entered a second
amended progression order. Again, other than the deadlines
for expert witness disclosures, the pertinent language did not
change. That language stated:
8. Expert Witnesses. At least ninety (90) days prior to
July 10, 2023, any Plaintiff who intends to call an expert
as a witness in the case shall disclose the expert to all
opposing parties. Any expert who [Elite Fleet] intend[s]
to call to respond to the testimony of an expert witness
of an opposing party must be disclosed to all opposing
parties at least sixty (60) days prior to July 10, 2023. Any
further rebuttal experts must be disclosed to all opposing
parties at least thirty (30) days prior to July 10, 2023.
The disclosures required in this paragraph shall identify
the proposed expert, including, without limitation, the
name, address, phone number, curriculum vitae and a
listing of all publications authored by the expert which
contain any discussion of concepts the expert will use in
expressing his or her opinions in this case. The disclosure
shall further contain a complete statement of the opinion
to be rendered and the basis therefor[]. Expert testimony
will not be permitted at trial unless it is contained in the
disclosure.
(Emphasis omitted.)
On April 17, 2023, Bazan served Elite Fleet with supple-
mental responses to Elite Fleet’s discovery requests. These
included an affidavit by Dr. Aguila, dated April 14, 2023.
That affidavit referred to records of Bazan’s treatment with
Dr. Aguila “as a result of” the collision, referenced attached
invoices for those services, and stated that Bazan continued to
receive treatment.

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Nebraska Supreme Court Advance Sheets
322 Nebraska Reports
BAZAN v. GONSER
Cite as 322 Neb. 54
On May 23, 2023, Elite Fleet filed a motion to strike Dr.
Aguila as a witness or to limit his opinions. Elite Fleet argued
that Bazan’s disclosures as to Dr. Aguila did not comply with
the second amended progression order’s direction to include
“a complete statement of the opinion to be rendered and the
basis therefor[]” by April 11. It acknowledged that Bazan had
provided Dr. Aguila’s treatment records, but it asserted that
“Dr. Aguila’s records do not contain a causation analysis, per-
manency analysis, future medical treatment analysis, or future
medical costs.”
On May 26, 2023, Bazan took Dr. Aguila’s trial deposition.
His testimony further explained his opinions on causation,
prognosis, and the resulting need for past and future medi-
cal care.
On June 9, 2023, Bazan provided to Elite Fleet “supplemen-
tal responses to [Elite Fleet’s] discovery requests and rebuttal
expert witness disclosures.” The document stated that all the
opinions contained in Dr. Aguila’s depositions “are hereby
disclosed as expected trial testimony.” The document also
included descriptions of Dr. Aguila’s potential trial testimony
based on his deposition testimony. Bazan prefaced each state-
ment about Dr. Aguila’s potential testimony “[a]s rebuttal.”
According to the document, Dr. Aguila would testify, based
on a medical article also cited in his May 2023 deposition,
that “over the course of [Bazan’s] crash-related treatment,” his
symptoms indicated that he suffered postconcussive syndrome,
a “‘constellation of symptoms that commonly occur after [an
mTBI].’” Bazan stated that Dr. Aguila would testify that “TBI
results from blunt force, nonpenetrating head trauma, trauma,
concussion, assault, or sports-related injuries.” Later in the
document, Bazan asserted that Elite Fleet’s truck “crashed
into [Bazan’s] vehicle at a high rate of speed and knocked
it off the I-80 roadway,” causing Bazan “to sustain damages
to his body.” Bazan asserted Dr. Aguila would testify that
Bazan had undergone procedures to treat the posttraumatic
headaches he suffered as a consequence of the collision and

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BAZAN v. GONSER
Cite as 322 Neb. 54
that the collision caused Bazan to develop a long-term need
for future care. The document disclosed the current cost of the
procedure Bazan had undergone, stated that Dr. Aguila would
testify about past and future medical costs, and referenced the
previously disclosed invoices.
(ii) Motion to Strike Dr. Aguila
Sustained, in Part
At a hearing on the motion to strike, the district court
received exhibits related to the discovery process. Following
the hearing, the district court entered an order sustaining the
motion to strike in part and overruling it in part.
The district court began by observing that “the disclosure
requirement at issue is pursuant to the progression orders,” spe-
cifically the second amended progression order “concern[ing]
experts intended to be [witnesses] in the case.” The district
court emphasized that the disclosure requirements of Nebraska
discovery rules were “not relevant for purposes of compliance
with the progression order.”
The district court’s order then summarized the discovery
procedure as follows:
After receiving input from counsel, a second amended
progression order with new deadlines was entered on
February 8, 2023. That order allowed [Bazan] until
April 11, 2023 to comply with the requirements for the
disclosure of experts . . . . As of the date of the hearing
of this motion, [Bazan has] not provided supplements to
[his] mandatory disclosures, served additional disclosures
required by the Second Amended Progression Order,
nor 	supplemented 	his 	discovery 	responses 	itemizing
damages.
The district court went on to address Dr. Aguila’s potential
trial testimony. It cited Gruttemeyer v. Transit Authority, 31
F.4th 638 (8th Cir. 2022), and stated: “While a treating phy-
sician may not usually be subject to the disclosure require-
ments as an expert, [he or she does] become subject to those

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BAZAN v. GONSER
Cite as 322 Neb. 54
requirements when testifying about matters outside the patient’s
treatment, such as causation.” The district court went on:
It is evident from Dr. Aguila’s deposition and affida-
vit offered in support of [Bazan’s] motion for summary
judgment that Dr. Aguila may have testimony regarding
causation, permanency, and future medical costs. This
evidence is outside the scope of that allowed for a treat-
ing physician and not timely disclosed as required by the
Second Amended Progression Order. Accordingly, that
evidence will not be allowed.
The district court ordered Dr. Aguila’s testimony on causation,
permanency, and future medical costs stricken. It ordered Dr.
Aguila’s testimony to be limited to his treatment of Bazan.
(iii) Dr. Aguila Testifies at Trial
Dr. Aguila, a medical doctor and board-certified ear, nose,
throat, and nerve specialist, testified at trial that he treated
Bazan for posttraumatic headaches and neck pain following
the collision. He testified that he diagnosed Bazan with an
mTBI based on Bazan’s report that he lost consciousness after
the accident. Despite Bazan’s offer of proof, which included a
table of past medical expenses, the district court made rulings
at trial that were consistent with its order striking Dr. Aguila’s
testimony on the issues of causation, permanency, and future
medical costs. As a result, evidence of past medical expenses
was not presented to the jury.
(b) Standard of Review
[1-3] Generally, the control of discovery is a matter for
judicial discretion, and decisions regarding discovery will
be upheld on appeal in the absence of an abuse of discre-
tion. Carrizales v. Creighton St. Joseph, 312 Neb. 296, 979
N.W.2d 81 (2022). Similarly, appellate review of a district
court’s use of inherent power is for an abuse of discretion. Id.
An abuse of discretion occurs when a trial court’s decision is
based upon reasons that are untenable or unreasonable or if

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BAZAN v. GONSER
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its action is clearly against justice or conscience, reason, and
evidence. Id.
(c) Analysis
Bazan assigns on appeal that the district court erred in
excluding Dr. Aguila’s testimony on the issues of causation
and prognosis and related testimony concerning past and future
medical expenses. To resolve this issue, we examine the district
court’s order partially sustaining Elite Fleet’s motion to strike
Dr. Aguila’s testimony, which the district court later upheld at
trial, and we ultimately conclude that the district court did not
abuse its discretion.
Bazan mainly claims that the district court’s “exclusion of
expert testimony was not merely a discretionary evidentiary
ruling; it was premised upon incorrect legal standards.” Reply
brief for appellant at 4. Bazan seems to argue that it was
Nebraska’s discovery and evidence rules that controlled the
district court’s ruling on the motion to strike and that the dis-
trict court erred by not adhering to those rules. For Dr. Aguila’s
opinions on causation, prognosis, and future medical expenses,
Bazan claims that he complied with Nebraska discovery rules
addressing disclosures about expert witnesses and gave Elite
Fleet ample notice of how Dr. Aguila would testify at trial.
See, e.g., Neb. Ct. R. Disc. § 6-326(b)(4). He also asserts Dr.
Aguila’s testimony about past and future medical expenses
was admissible under the Nebraska Rules of Evidence. See
Neb. Evid. R. 703, Neb. Rev. Stat. § 27-703 (Reissue 2016)
(addressing facts upon which expert witness may rely for opin-
ion to be admissible at trial).
We note that Bazan’s position—that the aforementioned
points of Nebraska law controlled the district court’s ruling
striking portions of Dr. Aguila’s testimony—appears to be a
response to the district court’s reference to a federal case. The
district court cited an Eighth Circuit case holding that if a
treating physician will testify about matters outside the realm
of treatment, such as causation of a condition, the treating

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BAZAN v. GONSER
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physician is a retained expert and the disclosure requirements
of Fed. R. Civ. P. 26 are triggered. See Gruttemeyer v. Transit
Authority, 31 F.4th 638 (8th Cir. 2022).
We acknowledge that the district court’s reference to the
federal case was not an aid to clarity. But we need not consider
the discovery and admissibility rules put forward by Bazan,
because a careful reading of the district court’s order reveals
that it was not on those grounds that it excluded portions of
Dr. Aguila’s testimony. The district court’s order partially
sustaining Elite Fleet’s motion to strike underscored that the
ruling did not implicate Nebraska discovery rules. Instead,
the district court expressly based its order on whether Bazan
had made disclosures in accordance with the second amended
progression order’s provisions regarding expert witnesses. It
stated that “the disclosure requirement at issue is pursuant to”
the district court’s second amended progression order and that
Nebraska discovery rules were “not relevant for the purposes
of compliance with the [second amended] progression order.”
The district court’s mention of the federal case does not call
this express statement into question. We understand the dis-
trict court to have referred to the federal case to differentiate
between subjects of expert testimony—causation, permanency,
and future medical costs—for which there was an inadequate
disclosure and other testimony that it would permit Dr. Aguila
to provide as a fact witness. And ultimately, the district court
reasoned that Dr. Aguila’s expert opinions on the issues of
causation, permanency, and future medical costs were not
timely disclosed as required by the second amended progres-
sion order. It therefore excluded them as a consequence, in
accord with the progression order’s warning that “[e]xpert
testimony will not be permitted at trial unless it is contained
in the disclosure.”
[4] Bazan makes no effort to dispute that the district court
had authority to enforce its second amended progression
order in this manner. And indeed, such an effort would be
futile. Nebraska courts, through their inherent judicial power,

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have the authority to do all things necessary for the proper
administration of justice. Putnam v. Scherbring, 297 Neb.
868, 902 N.W.2d 140 (2017). This inherent power authorizes
trial courts to issue and enforce progression orders related to
discovery. See, Carrizales v. Creighton St. Joseph, 312 Neb.
296, 979 N.W.2d 81 (2022); Putnam, supra. Consistent with
this authority, a trial court can strike testimony when a party
has not heeded a progression order. See id.
To the extent that Bazan highlights certain points in the
discovery process to claim he was in “direct compliance” with
the terms of the second amended progression order, indepen-
dent of his reliance on discovery rules, we are unpersuaded.
See reply brief for appellant at 9. Recall that the second
amended progression order required, among other things, that
disclosures “contain a complete statement of the opinion to be
rendered [by the expert] and the basis therefor[]” by April 11,
2023. It also ordered that “[a]ny further rebuttal experts must
be disclosed to all opposing parties at least thirty (30) days
prior to July 10, 2023.” As we will explain, Bazan does not
show disclosures concerning Dr. Aguila that amount to “com-
pliance” with the district court’s second amended progression
order. See id.
Bazan appears to assert that the disclosures he made on
December 15, 2022, fulfilled the second amended progres-
sion order’s requirements. On that date, Bazan disclosed
Dr. Aguila would testify “consistent with his medical records”
that “Bazan’s medical treatment was caused by the crash, rea-
sonable, necessary, and reasonably priced” and that the “inju-
ries suffered are permanent, progressive and painful,” requir-
ing ongoing medical care. We do not view these statements
as satisfying the second amended progression order because,
while they may have stated Dr. Aguila’s opinion in broad
strokes, they did not explain “the basis therefor[],” as required
by the second amended progression order: Neither the disclo-
sures nor the referenced medical records, which the district
court’s ruling on the motion in limine deemed inadequate to

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satisfy the language of the progression order, explained why
Dr. Aguila opined that the collision was the source of Bazan’s
injuries requiring medical treatment or provided an analysis of
Bazan’s need for future treatment and its projected cost.
Bazan seems to place significance on the fact that the
December 15, 2022, disclosures purported to incorporate by
reference Dr. Aguila’s future deposition testimony and that the
December 15 disclosures put Elite Fleet “on explicit notice
that Dr. Aguila’s opinions, once expressed in deposition, would
form part of the trial testimony.” Reply brief for appellant at
6. Bazan also appears to proffer the December 2022 deposi-
tion itself as compliance with the second amended progression
order. Bazan essentially asks us to equate notice to Elite Fleet
in any form with adherence to the specific requirements of the
second amended progression order.
We reject Bazan’s attempt to shift the focus to what Elite
Fleet might have known and away from the requirements of
the second amended progression order. We also reject his
suggestion that he could comply with the second amended
progression order by bootstrapping future deposition testi-
mony onto his December 15, 2022, disclosures. And as for the
December 2022 deposition, we reject Bazan’s position that it
complied with the second amended progression order’s expert
disclosure requirements.
We are skeptical that the content of the December 2022
deposition fulfilled the second amended progression order.
Upon examination by Elite Fleet, Dr. Aguila admitted that his
records did not include analyses regarding causation, perma-
nency, or future medical costs; that is, his previously disclosed
records did not “contain a complete statement of the opinion
to be rendered [by the expert] and the basis therefor[]” as
the second amended progression order required. As for the
remainder of the deposition, Dr. Aguila’s testimony did little
to expand on what his visit notes said about the cause of any
concussion. Nor did Dr. Aguila give any meaningful opinion
about permanency and future medical costs; he testified that

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Bazan could be at increased risk for certain conditions later
in life, but he also testified that Bazan could suffer either a
temporary aggravation or a permanent aggravation in the form
of headaches, for which Bazan was receiving treatment that he
would “likely need to have . . . repeated.”
And even if the deposition had disclosed what the second
amended progression order required, we do not accept that
Bazan could have used it to comply with the obligation the
progression order imposed. The second amended progression
order directed that Bazan “shall disclose” expert witnesses “to
all opposing parties” by a designated date. It then mandated
that such disclosure “shall identify” the expert by including
his or her name and curriculum vitae and by “listing” relevant
publications the expert had authored; the second amended
progression order continued that the disclosure “shall further
contain a compete statement of the opinion to be rendered and
the basis therefor[].” (Emphasis supplied.) We read this text to
communicate the district court’s expectation that Bazan dis-
close expert witnesses directly to Elite Fleet in a discrete writ-
ten format. This stands in contrast to Bazan’s expectation that
Elite Fleet should cobble together the necessary information
by referring to Bazan’s vague disclosures and medical records
and Elite Fleet’s own deposition of Dr. Aguila.
Bazan also calls our attention to Dr. Aguila’s affidavit,
which he maintains was dated and timely submitted on April
11, 2023, the second amended progression order’s deadline
for expert disclosures. But we need not discuss the affidavit’s
content because Bazan is mistaken in asserting it was timely:
Dr. Aguila’s affidavit was dated and notarized April 14, 2023,
and disclosed to Elite Fleet on April 17. Accordingly, we do
not view this affidavit as evidence that Bazan satisfied the
second amended progression order’s requirements.
Finally, Bazan attempts to style his June 9, 2023, disclo-
sures about Dr. Aguila’s testimony as “rebuttal disclosures.”
Reply brief for appellant at 8. As rebuttal expert disclosures,
Bazan seems to submit, they were timely under the language

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of the second amended progression order. He does not dispute
that if these disclosures were not made in rebuttal, they were
not timely under the second amended progression order, which
required primary expert disclosures by April 11. Thus, his
argument depends on whether the June 9 disclosures were in
fact rebuttal disclosures. Bazan apparently suggests that they
were by noting that the June 9 disclosures directly contradicted
Dr. Ernst’s opinion. We cannot agree that these disclosures
were timely under the second amended progression order.
“Rebuttal” is a legal term of art. See Morgan v. Commercial
U. Assur. 	Companies, 	606 	F.2d 	554 	(5th 	Cir. 	1979). 	In
Nebraska, in the context of evidence at trial, we have said that
rebuttal evidence is generally confined to that which explains,
disproves, or counteracts evidence introduced by the adverse
party; such rebuttal evidence is not intended to give a party
an opportunity to tell his story twice or to present evidence
that was proper in his case in chief. See Wright v. Forney, 233
Neb. 258, 444 N.W.2d 895 (1989). See, also, Westgate Rec.
Assn. v. Papio-Missouri River NRD, 250 Neb. 10, 547 N.W.2d
484 (1996); Cromer v. Farmland Service Coop, Inc., 198 Neb.
355, 252 N.W.2d 635 (1977); McClellan v. Hein, 56 Neb. 600,
77 N.W. 120 (1898).
A body of federal authority similarly describes rebuttal as
a response to the adverse party’s evidence, not an alternative
means to make the presenting party’s prima facie case. Faigin
v. Kelly, 184 F.3d 67, 85 (1st Cir. 1999) (“[t]he principal
objective of rebuttal is to permit a litigant to counter new,
unforeseen facts brought out in the other side’s case”); Braun
v. Lorillard, Inc., 84 F.3d 230, 237 (7th Cir. 1996) (“plaintiff
who knows that the defendant means to contest an issue that is
germane to the prima facie case . . . must put in his evidence
on the issue as part of his case in chief”); Cates v. Sears,
Roebuck & Co., 928 F.2d 679, 685 (5th Cir. 1991) (“[r]ebuttal
must be kept in perspective; it is not to be used as a continua-
tion of the case-in-chief”); Bell v. Progressive Select Ins. Co.,
692 F. Supp. 3d 1121, 1124-25 (M.D. Fla. 2023) (“as a matter

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of first principle, a rebuttal expert opinion must address new,
unforeseen evidence in the other party’s case or must address
matters on which the opposing party bears the burden of
proof, such as an affirmative defense. . . . A plaintiff’s rebuttal
expert may not simply raise evidence that goes to the plain-
tiff’s prima facie case”).
We find this view of rebuttal instructive in this case and
conclude that Bazan’s June 9, 2023, disclosures were not prop-
erly termed “rebuttal” disclosures under the second amended
progression order. The disclosures explained why Dr. Aguila
opined that the collision caused Bazan to sustain an mTBI
and explained the observed and expected course of Bazan’s
postconcussive symptoms, the need for past and future treat-
ment, and the cost of that treatment. These disclosures did not
address new issues raised by Elite Fleet’s disclosures or issues
for which Elite Fleet bore the burden of proof; rather, they
spoke directly to issues that Bazan was required to prove at
trial as part of his prima facie case. Bazan cannot satisfy the
requirements of the second amended progression order simply
by relabeling untimely primary expert disclosures as “rebut-
tal.” “[D]isagreeing with a defense expert on matters related
to a plaintiff’s case in chief does not transform a plaintiff’s
expert into a rebuttal expert and thereby permit a plaintiff to
evade a case management and scheduling order.” Bell, supra,
692 F. Supp. 3d at 1123. We therefore conclude that Bazan’s
June 9, 2023, “rebuttal” disclosures did not achieve compli-
ance with the second amended progression order.
In sum, we find no abuse of discretion in the district
court’s decision to exercise its authority to enforce its sec-
ond amended progression order by excluding portions of Dr.
Aguila’s testimony. Bazan’s assertion that the district court
applied the wrong legal rules is misplaced, and he has not
shown that he complied with the second amended progression
order’s directive to provide “a complete statement of the opin-
ion to be rendered” by Dr. Aguila “and the basis therefor[]”
by the designated date, lest the testimony be excluded at trial.

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The decision to exclude some of Dr. Aguila’s testimony was
also consistent with the district court’s order overruling Elite
Fleet’s motion in limine months before. That order informed
Bazan that his disclosures at that time were insufficient to
satisfy the language of the then-operative progression order,
language that the district court retained in every subsequent
progression order. Despite this warning, Bazan made no mean-
ingful and timely additions to his disclosures about Dr. Aguila
to bring him into compliance with the second amended pro-
gression order. Bazan has offered us no basis to conclude that
the district court’s decision to exclude portions of Dr. Aguila’s
testimony was based on reasons that were untenable or unrea-
sonable or that the district court clearly acted against justice or
conscience, reason, and evidence. See Putnam v. Scherbring,
297 Neb. 868, 902 N.W.2d 140 (2017).
2. Dr. Ernst
(a) Background
Prior to trial, Bazan filed a motion to strike the testimony
of Dr. Ernst. Bazan contended that as a psychologist, Dr. Ernst
was not qualified to give “medical” testimony regarding “med-
ical” criteria for diagnosing an mTBI and regarding whether
Dr. Ernst agreed with Dr. Aguila, a medical doctor, that Bazan
incurred an mTBI in the collision.
At a hearing on the motion to strike, the district court
received an affidavit by Dr. Ernst explaining his qualifications
and referring to his attached curriculum vitae. According to the
curriculum vitae, Dr. Ernst had completed a doctoral degree
in clinical psychology and a postdoctoral residence in clinical
neuropsychology. His employment history included 8 years as
a staff neuropsychologist at a rehabilitation hospital for adults
with acute traumatic brain injuries. A few years before the
affidavit, Dr. Ernst had given a presentation at a conference on
the assessment and treatment of neuropsychological function
after an mTBI.

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In the affidavit, Dr. Ernst described himself as a neu-
ropsychologist and stated that “[c]oncussion/mTBI diagno-
sis and treatment involves neurology and neuropsychology.”
According to Dr. Ernst’s affidavit, neuropsychology is a “rec-
ognized area of specialization in psychology.” Dr. Ernst stated
that he passed the training, licensure, and qualifications com-
mon to most psychologists and that, as a neuropsychologist,
he had taken numerous university-based courses in the neu-
rosciences. In addition, consistent with his curriculum vitae,
he said he was classified as a “‘medical psychologist’” by
the U.S. Drug Enforcement Agency and licensed in Iowa to
interpret laboratory tests and brain imaging, “such as MRIs
and CT scans.”
Also attached to the affidavit was Dr. Ernst’s report on his
evaluation of Bazan, which included a consultation with Bazan
and a review of his medical and psychological history, as well
as accident records. At the time Dr. Ernst authored his report
on Bazan, he was licensed as a psychologist in Nebraska and
Iowa. Dr. Ernst stated that he performed an interview and neu-
ropsychological testing of Bazan. Dr. Ernst opined that based
upon the evidence, including medical records and accident
reports, Bazan did not suffer a “concussion/mTBI.”
The district court overruled Bazan’s motion to strike tes-
timony by Dr. Ernst. It observed that Ernst was a licensed
psychologist with a doctoral degree in clinical psychology and
a postdoctoral residence in clinical neuropsychology. Citing
Nebraska statutes, the district court reasoned that Dr. Ernst’s
actions and opinions were within the scope of the practice of
psychology as defined by Nebraska law.
At trial, Bazan renewed his motion to strike, and the district
court again overruled it. Over Bazan’s standing objection, Dr.
Ernst opined, within a reasonable degree of medical certainty,
that Bazan did not suffer a brain injury in the collision. Over
Bazan’s objection, Dr. Ernst testified why he disagreed with
Dr. Aguila’s opinion that Bazan had an mTBI.

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(b) Standard of Review
[5] There is no exact standard for fixing the qualifications
of an expert witness, and a trial court is allowed discretion
in determining whether a witness is qualified to testify as an
expert. Yagodinski v. Sutton, 309 Neb. 179, 959 N.W.2d 541
(2021). Unless the court’s finding is clearly erroneous, such a
determination will not be disturbed on appeal. Id.
[6] An appellate court reviews de novo whether the trial
court applied the correct legal standards for admitting an
expert’s testimony, and it reviews for abuse of discretion how
the trial court applied the appropriate standards in deciding
whether to admit or exclude an expert’s testimony. Id.
(c) Analysis
Bazan contends that the district court erred in allowing Dr.
Ernst to opine that Bazan did not sustain an mTBI. And he
submits that this alleged error was “particularly egregious”
because Dr. Ernst’s testimony “directly contradicted Bazan’s
treating physician, Dr. Aguila, a licensed medical doctor” and
“improperly elevated [Dr.] Ernst’s testimony over that of a
licensed physician.” Brief for appellant at 36.
[7] We understand Bazan to argue that Dr. Ernst’s testimony
was inadmissible under Neb. Evid. R. 702, Neb. Rev. Stat.
§ 27-702 (Reissue 2016). That rule governs the admissibil-
ity of expert testimony and provides: “If scientific, technical,
or other specialized knowledge will assist the trier of fact to
understand the evidence or to determine a fact in issue, a wit-
ness qualified as an expert by knowledge, skill, experience,
training, or education, may testify thereto in the form of an
opinion or otherwise.” Under rule 702, a witness can testify
concerning scientific, technical, or other specialized knowl-
edge only if the witness is qualified as an expert. Carlson v.
Okerstrom, 267 Neb. 397, 675 N.W.2d 89 (2004). Whether a
witness is qualified as an expert is a preliminary question for
the trial court. Id.

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In short, the premise of Bazan’s position is this: The diagno-
sis of an mTBI is the practice of medicine, and a psychologist
cannot practice medicine. Assuming for the sake of argument
that an mTBI is a medical diagnosis and that Dr. Ernst’s opin-
ion was one such diagnosis, Bazan’s reasoning depends on
the idea that “Nebraska law draws a clear line between the
practice of medicine and the practice of psychology.” Brief for
appellant at 31. As we are about to illustrate, these arguments
do not persuade us.
In his attempt to completely isolate the practice of psychol-
ogy from the practice of medicine in Nebraska, Bazan relies
on our rule 702 analysis in Yagodinski v. Sutton, 309 Neb.
179, 959 N.W.2d 541 (2021). But Bazan misreads our reason-
ing in Yagodinski.
In Yagodinski, we affirmed the district court’s ruling that
a chiropractor was not qualified to give expert opinion testi-
mony that his patient sustained a traumatic brain injury, on the
basis that the chiropractor’s diagnostic methods fell outside
the scope of chiropractic practice in Nebraska as defined by
the Legislature. Our analysis identified the statutory scope
of practice established by the Legislature as “a factor affect-
ing qualification” of a “licensed health professional offering
[expert] testimony about a patient.” Id. at 198, 959 N.W.2d at
554. Citing Neb. Rev. Stat. § 38-2025(13) (Cum. Supp. 2024),
we recognized that a chiropractor is excluded “from the class
of persons who engage in the unauthorized practice of medi-
cine, so long as the chiropractor is ‘licensed and practicing
under the Chiropractic Practice Act.’” See Yagodinski, 309
Neb. at 192, 959 N.W.2d at 551.
We observed in Yagodinski that a licensed chiropractor will
generally be qualified to testify as an expert on any matter
that is within the scope of chiropractic practice and licensure
in Nebraska; but after a detailed discussion of the statutes
that defined that scope, we concluded that the chiropractor’s
diagnosis in that case was outside of it. In so holding, we
declined to read the statutory scope of chiropractic practice

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“so broadly” as to permit “licensed chiropractors to diagnose
all human conditions without limitation” because such a read-
ing “would expand the authorized diagnostic methods to be
commensurate with licensed physicians and surgeons.” Id. at
195, 959 N.W.2d at 552. See, also, Neb. Rev. Stat. § 38-2024
(Reissue 2016) and § 38-2025. We further explained that “no
amount of additional education will qualify a licensed chiro-
practor to offer expert testimony about a patient that is outside
the scope of chiropractic practice in Nebraska, absent addi-
tional licensure and credentialing” enacted by the Legislature.
Yagodinski, 309 Neb. at 200, 959 N.W.2d at 555.
Bazan 	reads 	Yagodinski 	to 	hold 	that 	“[n]on-[m]edical
[p]rofessionals,” brief for appellant at 31, such as chiroprac-
tors and psychologists, are not qualified to diagnose “physical,
medical injur[ies]” and that a traumatic brain injury is one such
injury, id. at 32. Again, assuming for the sake of argument that
an mTBI is a medical diagnosis and that Dr. Ernst’s opinion
qualified as a diagnosis, Bazan’s position hangs on the notion
that there is no overlap between the practice of medicine and
the practices of other licensed health professions. However,
Yagodinski did not hold, as Bazan submits, that chiropractors
and other licensed health professionals cannot practice medi-
cine. Yagodinski reasoned that as a class of licensed health
professionals enumerated in § 38-2025, chiropractors cannot
lawfully practice medicine to the same degree that medical
doctors, physicians, and surgeons can. See § 38-2025(13).
See, also, Neb. Rev. Stat. § 38-805(1) (Reissue 2016) (defin-
ing scope of chiropractic diagnosis and treatment).
Pursuant to Yagodinski, the key to whether Dr. Ernst was
qualified to testify here is not whether he was engaged in the
practice of medicine; the key instead is whether his opinion
testimony falls within the statutory ambit of his licensed health
profession. To be sure, to avoid the unauthorized practice of
medicine in Nebraska, psychologists must be “licensed to prac-
tice in this state and practicing under and in accordance with
the Psychology Interjurisdictional Compact or the Psychology

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Practice Act.” See § 38-2025(15). But Bazan has made no rea-
soned attempt to demonstrate to us that Dr. Ernst acted outside
the scope of the practice of psychology as the Legislature has
defined it.
Under Neb. Rev. Stat. § 38-3108(2) (Reissue 2016), the
practice of psychology “includes, but is not limited to . . .
the evaluation or assessment of . . . neuropsychological func-
tioning [and] diagnosis and treatment of . . . the psychological
aspects of physical illness, accident, injury, or disability.” In
addition, the Legislature has authorized neuropsychologists
to determine whether a minor athlete can return to play after
a suspected brain injury. See Neb. Rev. Stat. §§ 71-9103 and
71-9105 (Reissue 2018) (authorizing physician, certified ath-
letic trainer, or neuropsychologist, among others, to make ini-
tial determination that minor athlete is reasonably suspected
of having sustained concussion or brain injury, to evaluate
minor athlete thereafter, and to give written and signed clear-
ance to resume participation). Dr. Ernst is a doctor of clinical
psychology with a specialization in neuropsychology, who
was licensed as a psychologist in Nebraska as of the date
of his report on Bazan. In explaining his qualifications, Dr.
Ernst stated that “[c]oncussion/mTBI diagnosis and treatment
involves neurology and neuropsychology.” After an evalua-
tion of Bazan, Dr. Ernst opined that he had not sustained an
mTBI. Bazan has not explained how, given all these facts,
Dr. Ernst acted outside the statutory scope of the practice
of psychology.
In arguing that Dr. Ernst’s license does not allow him to
“practice medicine in Nebraska,” Bazan makes a fleeting
contention that Dr. Ernst is not licensed to practice neuropsy-
chology in Nebraska, where he is “licensed only to practice
psychology.” Brief for appellant at 36. We are dubious that
Bazan made this argument with sufficient specificity before
the district court for us to address it on appeal. See White
v. White, 320 Neb. 256, 26 N.W.3d 924 (2025) (this court
will not consider argument or theory raised for first time on

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appeal, because lower court cannot commit error in resolv-
ing issue never presented and submitted to it for disposition).
But even if he did, Dr. Ernst explained that neuropsychol-
ogy was a specialty within psychology, for which he was
licensed in Nebraska at the time of his report on Bazan.
Consequently, even if we understood Bazan to claim that Dr.
Ernst acted outside the statutory scope of his profession, his
claim lacks merit.
Provided with no convincing argument that Dr. Ernst gave
an impermissible medical opinion that exceeded the statutory
scope of the practice of psychology, we circle back to the lan-
guage of rule 702 to decide whether the district court erred in
ruling that Dr. Ernst was “qualified as an expert by knowledge,
skill, experience, training, or education” to testify whether
Bazan had suffered an mTBI. On this topic, we have little
more to add. Dr. Ernst explained that he used his expertise as a
neuropsychologist to opine whether Bazan sustained an mTBI.
Bazan has not persuaded us that Dr. Ernst crossed the statutory
boundaries of his profession, and he offers no other argument
that Dr. Ernst was not qualified as an expert by knowledge,
skill, experience, or education. Accordingly, he gives us no
reason to hold that the district court abused its discretion in
allowing Dr. Ernst to testify regarding whether Bazan sustained
an mTBI. And insofar as Dr. Ernst’s opinion contradicted the
opinion of Dr. Aguila, a medical doctor and Bazan’s treating
physician, that presented a question of weight and credibility
for the jury to decide. See Estate of Block v. Estate of Becker,
313 Neb. 818, 986 N.W.2d 726 (2023).
V. CONCLUSION
We are unconvinced by Bazan’s arguments that the dis-
trict court erred in its rulings concerning expert testimony.
Consequently, we affirm.
Affirmed.