Prososki v. Regan

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
Jennifer M. Prososki, appellee and
cross-appellant, v. Jason C. Regan,
appellant and cross-appellee.
___ N.W.3d ___
Filed March 20, 2026. 	No. S-25-295.
1. Rules of the Supreme Court: Appeal and Error. Where a brief
of a party fails to comply with the mandate of Neb. Ct. R. App. P.
§ 2-109(D)(1)(e) (rev. 2025), an appellate court may proceed as though
the party failed to file a brief or, alternatively, may examine the proceed-
ings for plain error.
2. Appeal and Error. Plain error is error plainly evident from the record
and of such a nature that to leave it uncorrected would result in damage
to the integrity, reputation, or fairness of the judicial process.
3. Divorce: Property Division. The extent to which the property is marital
versus nonmarital presents a mixed issue of law and fact.
4. Evidence: Appeal and Error. In a review de novo on the record, an
appellate court is required to make independent factual determina-
tions based upon the record, and the court reaches its own independent
conclusions with respect to the matters at issue. When evidence is in
conflict, the appellate court considers and may give weight to the fact
that the trial court heard and observed the witnesses and accepted one
version of the facts rather than another.
5. Expert Witnesses. The determination of the weight that should be given
expert testimony is uniquely the province of the fact finder.
6. Appeal and Error. Appellate courts do not generally consider argu-
ments and theories raised for the first time on appeal.
7. Disciplinary Proceedings: Intent. Proof of actual intent to deceive or
defraud is not required to demonstrate an attorney engaged in conduct
involving dishonesty, fraud, deceit, or misrepresentation. Instead, the
focus of the inquiry is on the effect of the lawyer’s conduct.
Nebraska Supreme Court Online Library
www.nebraska.gov/apps-courts-epub/
10/18/2026 12:49 AM CDT

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
8. Rules of the Supreme Court: Disciplinary Proceedings: Attorneys at
Law. Acts or omissions by members of the Nebraska bar which violate
the Nebraska Rules of Professional Conduct are grounds for discipline.
9. Divorce: Property Division. Any given property can constitute a mix-
ture of marital and nonmarital interests; a portion of an asset can be
marital property while another portion can be separate property.
10. ____: ____. Appreciation, be it active or passive, in the marital interest
is always marital; it is simply part of the marital property.
11. Divorce: Property Division: Equity. Premarital equity in real property
is a nonmarital asset which, if established, should be set aside as sepa-
rate property.
12. Divorce: Property Division: Proof. The burden of proof rests with the
party claiming that the property is nonmarital.
13. Proof. A fact finder cannot reach conclusions based on guess, specula-
tion, or conjecture, because conjecture, speculation, or choice of quanti-
tative possibilities are, of course, not proof.
Appeal from the District Court for Douglas County: Tressa
M. Alioth, Judge. Affirmed in part, and in part dismissed.
W. Gregory Lake, of Plains Legal Group, for appellant.
Benjamin M. Belmont and Mariah E. Shaffer, of Brodkey,
Cuddigan, Peebles, Belmont & Line, L.L.P., for appellee.
Michael T. Hilgers, Attorney General, Cody S. Barnett,
Zachary 	B. 	Pohlman, 	and 	Katelyn 	(Miller) 	Rich, 	Senior
Certified Law Student, for amicus curiae Attorney General.
Funke, C.J., Cassel, Stacy, Papik, Freudenberg, and
Bergevin, JJ.
Per Curiam.
INTRODUCTION
We moved this appeal of a decree of dissolution of mar-
riage to our docket to address numerous nonexistent or inac-
curate case citations and quotations in the appellant’s brief,
which the appellee/cross-appellant asserts are the product
of generative artificial intelligence (AI). The appellee/cross-
appellant moved to strike the appellant’s brief and dismiss

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
the appeal. The appellant moved for leave to replace the
original brief. We initially overruled each motion. We now
strike the appellant’s brief, dismiss the appellant’s appeal, and
refer the appellant’s counsel to the Counsel for Discipline of
the Nebraska Supreme Court. Finding no merit to the cross-
appeal, we affirm the judgment of the district court.
BACKGROUND
Factual and Procedural Background
Jennifer M. Prososki (Jennifer) and Jason C. Regan (Jason)
were married in 2012. The couple had one child, born in 2014.
They have been informally separated since 2016, although they
were briefly separated in 2013 and were briefly together from
time to time after 2016. The present dissolution action was
filed by Jennifer in January 2023. Prior complaints for dissolu-
tion were filed in 2013 and 2016 but were later dismissed.
In her complaint for dissolution, Jennifer sought joint legal
custody of the minor child, sole physical custody of the minor
child, an award for child support, and an equitable division of
marital assets. During the pendency of the proceedings, the
district court issued two temporary orders related to parenting
time of the minor child. The parties also went through several
discovery disputes, involving a deposition of Jennifer’s daugh-
ter from a previous marriage, Jason’s attempt to strike one of
Jennifer’s expert witnesses, and Jason’s moving for sanctions
against Jennifer and her counsel for alleged discovery viola-
tions. The trial did not take place until 2025, after which the
decree of dissolution was entered.
At trial, Jennifer’s counsel argued that 2016 should be the
effective date of division of the assets; thus, the timeframe
for “looking at dividing assets that were acquired through
the joint efforts of the parties” was between 2012 and 2016.
Jason’s counsel did not dispute this premise. Jennifer testified
that since 2016, she and Jason had not acquired any assets nor
incurred any debts through their joint efforts. Jason testified
that since 2016, he and Jennifer did not have any joint bank

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
accounts or joint debt. Jennifer’s counsel reiterated after trial
that a property division date of August 2016 was appropriate
because there were no assets or debts acquired through the
joint efforts of the parties after that date.
Jennifer and Jason each own real property that they pur-
chased before the marriage. Jennifer purchased a house in 2008
from Jason. Jason owns a duplex next door to Jennifer, which
he purchased in 2005.
Jennifer purchased her house in 2008 for $100,000. Jennifer
called an expert witness, a licensed real estate appraiser, to
establish retrospective appraisals of her house. The appraiser
testified that the appraised value of the house at the time
the parties were married in 2012 was $85,000 and that the
appraised value of the house in 2016 was $100,000.
A mortgage statement from January 2012 demonstrated
the outstanding mortgage on Jennifer’s house was approxi-
mately $91,600 at the time of marriage. A mortgage state-
ment from August 2016 demonstrated the outstanding balance
was approximately $74,500 at the time of their informal
separation. Thus, during the period of the marriage before the
informal separation, the mortgage balance was reduced by
approximately $17,000. Jennifer indicated that Jason did not
contribute to the mortgage payments or taxes on the house
after 2016.
Jason testified that he purchased his duplex for approximately
$143,000 in 2005. Neither party provided expert appraisal tes-
timony regarding any past or present values of the duplex.
Jason testified he believed the duplex was valued about the
same when he and Jennifer were married in 2012, as well as
when they separated in 2016. However, Jason later testified
he did not have a clear opinion of the value of the duplex in
2016. Jennifer testified that, based on comparable sales and
per-square-footage pricing information she obtained online,
she estimated the value of Jason’s duplex at the time of their
separation in 2016 to be $169,012. Jennifer could not provide
comparable sales information at trial. She could not remember

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
any details about the comparable sales, such as square foot-
age or number of bedrooms. She admitted she did not have
any specialized training in real estate or appraisals. Neither
party provided any information as to the extent the duplex
was encumbered before their separation in 2016 or as to the
mortgage payments made during that period.
At a hearing on Jason’s counsel’s motions for sanctions
and to strike, Jennifer’s counsel pointed out that Jason never
produced mortgage statements from 2012 and 2016, as per
Jennifer’s requests for production. However, Jennifer never
sought enforcement of her discovery requests and did not
seek sanctions or other actions for Jason’s failure to produce
these documents.
At trial, the court sustained Jennifer’s counsel’s founda-
tion objection to Jason’s counsel’s attempts to adduce Jason’s
testimony as to what his duplex was appraised for in 2023.
However, Jason was permitted to testify that he believed the
value of the duplex in 2023 was $165,080. Jason had spe-
cialized training in real estate but, at the time of trial, was
no longer a certified appraiser. Jason testified in his pretrial
deposition that he believed the duplex was worth around
$160,000 when Jennifer filed for dissolution in 2023. Jason
also testified in his deposition that he had to take out a home
equity loan in 2023 to pay his counsel and that an appraisal
associated with the loan valued the duplex at $245,000. An
exhibit entered in evidence reflects an appraisal report in
2021, which was for purposes of refinancing, valuing the
duplex at $260,000. The document states that the appraisal
was for the purpose of “mortgage financing only.” Jennifer
testified that Jason did extensive remodeling of the duplex
after they separated in 2016. Jason testified in his deposition
that he had spent about $55,000 remodeling the duplex after
their separation.
Jason testified at trial that, as of the date of filing, he still
owed $97,279.36 on his first mortgage on the duplex. A mort-
gage statement entered in evidence also reflects that balance.

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
Jason testified he took out a second mortgage on the duplex to
pay attorney fees.
The district court set forth in its decree that each party
owned their own real estate and shall be awarded the real
estate currently in their possession free and clear of any inter-
est from the other party and shall hold the other free and harm-
less from any and all liability for debts maintained or titled in
his or her own individual name associated with the real estate.
The court did not order any equalization payment in relation
to the real estate.
In a subsequent order on a motion to alter or amend the
decree, the court observed that the marital estate consisted of
the motor vehicles owned at the time of separation and did not
include the real estate. The court did not make any specific
findings as to the amounts the mortgage payments made dur-
ing the marriage acquired equity in the house and the duplex
or whether the mortgage payments on the real estate were
from marital or nonmarital funds. Nor did it make any specific
findings on appreciation.
The decree granted joint legal custody of the couple’s minor
child and granted sole physical custody of the minor child to
Jennifer, subject to Jason’s parenting time. Jason was ordered
to pay child support, and the parties were ordered to split
expenses related to the minor child.
Jason then filed this appeal. Jennifer cross-appealed.
Motions on Appeal
Jason’s counsel filed his appellate brief on July 31, 2025.
The next day, Jason’s counsel submitted a replacement brief in
which he added a required section that was missing from his
original brief but made no other changes to the original brief’s
content. At oral argument, Jason’s counsel asserted that he
attempted to file the “correct version” of his brief the day after
its initial filing. Despite this assertion, however, there is no
record of any such filing. Jason’s counsel made no attempts to
address the questionable contents of his brief until after Jennifer

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
filed a motion to strike Jason’s brief and dismiss Jason’s
appeal. In her motion, filed on August 26, Jennifer asserted
that Jason’s appellate brief contained many fictitious citations,
citations to real cases with incorrect holdings, and nonexis-
tent quotations. Jennifer argued that these errors violated the
Nebraska Rules of Professional Conduct, the Nebraska Court
Rules of Appellate Practice, and Nebraska’s statute governing
frivolous actions. Jennifer’s motion highlighted examples of
fake or incorrect citations and provided a chart showcasing
several examples of fake or incorrect citations.
In lieu of responding to Jennifer’s motions, Jason’s counsel
filed two nearly identical motions for leave to file a corrected
appellate brief. In his motions, Jason’s counsel stated the
citations in the original brief were “sloppy” due to “copying
and pasting . . . from Westlaw without verifying the official
reporter.” Jason’s counsel asserted he did not invent cases,
did not rely on AI, and did not attempt to mislead the court.
Jason’s counsel also addressed a few of the incorrect citations
from the original brief.
Jason’s counsel attributed the errors to the circumstances
surrounding the filing of the brief. First, he explained that his
motion for extension of time to file the brief was not granted
until July 31, 2025—the date the brief was due. Jason’s
counsel claimed this extension left him with “essentially no
additional time to finalize the brief.” Second, Jason’s counsel
explained that his computer suffered a “catastrophic screen
crack” on July 31 while he was traveling, leaving him without
a computer for 5 days. Jason’s counsel argued that granting
leave to replace his original brief would not prejudice Jennifer,
would protect the court’s integrity, and would protect Jason’s
right to an appeal. We overruled each motion.
After the case was moved to our docket, Jennifer filed her
appellate brief. Jason’s counsel moved for a time extension
to reply to Jennifer’s brief, but his motion was overruled for
failure to show exceptional cause. Jason’s counsel nonetheless
filed an untimely reply brief, which was stricken.

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
Jason’s Operative Brief
Jason’s July 31, 2025, brief contains numerous citations
to fake cases, real cases with fake quotations, real cases with
mischaracterized holdings, and Nebraska statutes and court
rules with fake quotations. Jason’s brief was signed and
certified by his counsel. An example of Jason’s reliance on
fictitious authority is as follows: “In Kennedy v. Kennedy,
27 Neb. App. 510, 934 N.W.2d 57 (2019), the court reversed
a parenting time order because it lacked specific findings
explaining why the reduced parenting time was in the child’s
best interest.” 1 “Kennedy v. Kennedy” is the name of a real
case decided by the Nebraska Court of Appeals in an unpub-
lished memorandum opinion filed in 2019, which does not
correspond to the citation given. 2 Furthermore, the unpub-
lished memorandum opinion does not stand for the proposi-
tion advanced by Jason. The only real “Kennedy v. Kennedy”
case decided by a Nebraska appellate court in 2019 does
not discuss parenting time, and it does not mention the need
for specific findings. Further, Jason’s brief includes a block
quotation from “Kennedy v. Kennedy” that does not exist
in the unpublished memorandum opinion; nor does it appear
to exist anywhere in Nebraska case law. Jason’s brief cites
repeatedly to “Kennedy v. Kennedy, 27 Neb. App. 510, 934
N.W.2d 57 (2019),” to support his contention that joint cus-
tody is favored when, in reality, Nebraska law does not favor
or disfavor any particular custody arrangement and requires
custody determinations to be made based on the best interests
of the child. 3
Jason’s brief also cites real cases with real reporter cita-
tions but misstates what the cases stand for or includes quotes
1 Brief for appellant at 13.
2 See Kennedy v. Kennedy, No. A-18-824, 2019 WL 2754981 (Neb. App.
July 2, 2019) (selected for posting to court website).
3 See State on behalf of Kaaden S. v. Jeffery T., 303 Neb. 933, 932 N.W.2d
692 (2019).

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
that cannot be found in the cited cases. For example, Jason’s
brief cites to “Simons v. Simons, 312 Neb. 136, 978 N.W.2d
121 (2022),” a real decision from this court, to support a
proposition that an appellate court will reverse a denial of
attorney fees when the record demonstrates that one party
caused delay or engaged in bad faith litigation tactics and the
trial court failed to consider or account for those actions. 4
Simons v. Simons 5 does not support this proposition or address
the denial of attorney fees. The only mention of attorney fees
in Simons is in the standard of review in a section discussing
alimony. Further, Jason’s brief provides, “‘A party is entitled
to be informed of the issues raised, and cannot be expected
to defend against a theory not disclosed in the pleadings.’
Simons v. Simons, 312 Neb. 136, 147, 978 N.W.2d 121, 131
(2022).” 6 This quote attributed to Simons does not exist
within the case, nor does it appear to exist in Nebraska case
law. Simons is misstated and misquoted several more times
throughout the brief.
Jason’s brief also contains misquotations from Nebraska
statutes and Supreme Court rules. For example, Jason’s brief
purports to quote Neb. Rev. Stat. § 43-2923(1) (Reissue 2016)
as stating, “‘Parenting arrangements should ensure frequent,
continuing, and meaningful contact with both parents as is in
the child’s best interests.’” 7 However, § 43-2923 actually states
in part, “The best interest of the child require: (1) A parenting
arrangement and parenting plan or other court-ordered arrange-
ment which provides for a child’s safety, emotional growth,
health, stability, and physical care and regular and continuous
school attendance and progress for school-age children.”
Jason’s brief contains many more incidents of his reliance
on fictitious authority, real cases with fictitious holdings, and
4 Brief for appellant at 31.
5 Simons v. Simons, 312 Neb. 136, 978 N.W.2d 121 (2022).
6 Brief for appellant at 28.
7 Id. at 8.

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PROSOSKI v. REGAN
Cite as 321 Neb. 38
fictitious quotations. The following chart depicts the many
problematic citations in Jason’s brief:
Jason’s Citation 	Result of This Court’s
Review
Kennedy v. Kennedy, 27
Neb. App. 510, 934 N.W.2d
57 (2019)
• Fictitious case using real
case name from unpub-
lished memorandum
opinion
• Cited and quoted five times
throughout brief
• Quotes and holding do not
exist in the real unpub-
lished memorandum
opinion or other Nebraska
case law
State on behalf of Maddox S.
v. Matthew E., 23 Neb. App.
500, 874 N.W.2d 211 (2016)
• Incorrect citation
• Does not support cited
proposition
• Fictitious quotations
Neb. Rev. Stat. § 43-2923 	• Real statute
• Fictitious quotations and
misleading application
throughout brief
Schrag v. Spear, 312 Neb.
88, 978 N.W.2d 591 (2022)
• Incorrect citation
• Fictitious quotations
Neb. Ct. R. § 4-204 	• Real court rule
• Fictitious quotation
Hotz v. Hotz, 301 Neb. 102,
917 N.W.2d 467 (2018)
• Real case
• Fictitious quotations and
holding throughout brief

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
State ex rel. A.E. v.
Buckhalter, 273 Neb. 443,
730 N.W.2d 340 (2007)
• Real case
• Does not stand for proposi-
tion cited to support
Schuman v. Schuman, 27
Neb. App. 1004, 939 N.W.2d
374 (2020)
• Incorrect citation
Neb. Ct. R. § 4-215 	• Real court rule
• Fictitious quotation
Miller v. Miller, 227 Neb.
71, 416 N.W.2d 358 (1987)
• Fictitious case
• Fictitious quotation
Crawford v. Crawford, 263
Neb. 37, 637 N.W.2d 505
(2002)
• Incorrect citation
• Fictitious quotation
Brown v. Brown, 260 Neb.
954, 620 N.W.2d 82 (2000)
• Incorrect citation
• Does not support cited
proposition
State on behalf of Ricardo
P. v. Christina R., 309 Neb.
705, 962 N.W.2d 315 (2021)
• Fictitious case
Bergmeier v. Bergmeier, 296
Neb. 440, 894 N.W.2d 266
(2017)
• Real case
• Fictitious quotations and
holding throughout brief
Simons v. Simons, 312 Neb.
136, 978 N.W.2d 121 (2022)
• Real case
• Fictitious quotations and
holding throughout brief
Parde v. Parde, 258 Neb.
101, 602 N.W.2d 657 (1999)
• Real case
• Fictitious quotations and
holding throughout brief

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Nebraska Supreme Court Advance Sheets
321 Nebraska Reports
PROSOSKI v. REGAN
Cite as 321 Neb. 38
Garza v. Garza, 288 Neb.
213, 846 N.W.2d 626 (2014)
• Real case
• Fictitious quotation and
holding
Heald v. Heald, 259 Neb.
604, 611 N.W.2d 598 (2000)
• Real case
• Does not support cited
proposition
Walker v. Walker, 9 Neb.
App. 834, 621 N.W.2d 535
(2001)
• Incorrect citation
• Fictitious quotation
State v. Stricklin, 29 Neb.
App. 367, 904 N.W.2d 535
(2017)
• Fictitious case
• Fictitious quotation
ASSIGNMENTS OF ERROR
Jason’s noncompliant, unnumbered assignments of error 8
assert that the district court (1) abused its discretion by
reducing his parenting time below what was ordered in the
temporary decree without making specific findings as to why
the reduction was in the best interests of the minor child; (2)
erred in imputing income to him at rates unsupported by the
record and without making a finding that he was voluntarily
underemployed; (3) failed to clarify its legal custody designa-
tion, while requiring him to contribute to direct expenses in a
manner consistent with a joint custody agreement; (4) failed
to consider or make findings regarding joint physical custody;
(5) erred in selecting August 1, 2016, as the date of marital
separation; (6) abused its discretion in awarding Jennifer a
$60,000 dissipation credit; (7) erred in awarding Jennifer
$16,616 in equalization based on vague or incomplete prop-
erty valuation evidence and an inconsistent application of
valuation dates; and (8) abused its discretion by denying his
8 See Neb. Ct. R. App. P. § 2-109(D)(1)(e) (rev. 2025) (numbering required).

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PROSOSKI v. REGAN
Cite as 321 Neb. 38
request for attorney fees. Jason also asserts the combined
effect of the above errors rendered the proceedings fundamen-
tally unfair, warranting reversal and a new trial.
On cross-appeal, Jennifer asserts that the trial court erred
in failing to include the real estate when equalizing the mari-
tal estate.
STANDARD OF REVIEW
[1,2] Where a brief of a party fails to comply with the man-
date of § 2-109(D)(1)(e), we may proceed as though the party
failed to file a brief or, alternatively, may examine the proceed-
ings for plain error. 9 Plain error is error plainly evident from
the record and of such a nature that to leave it uncorrected
would result in damage to the integrity, reputation, or fairness
of the judicial process. 10
[3] The extent to which the property is marital versus non-
marital presents a mixed issue of law and fact. 11 The manner
and method of acquisition involve questions of fact, but the
classification of the property under those facts is a legal ques-
tion and not a matter of the court’s discretion. 12
[4] In a review de novo on the record, an appellate court
is required to make independent factual determinations based
upon the record, and the court reaches its own independent
conclusions with respect to the matters at issue. However,
when evidence is in conflict, the appellate court considers
and may give weight to the fact that the trial court heard and
observed the witnesses and accepted one version of the facts
rather than another. 13
9 Swicord v. Police Stds. Adv. Council, 309 Neb. 43, 958 N.W.2d 388
(2021).
10 Id.
11 Stava v. Stava, 318 Neb. 32, 13 N.W.3d 184 (2024).
12 Id.
13 Seivert v. Alli, 309 Neb. 246, 959 N.W.2d 777 (2021).

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PROSOSKI v. REGAN
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[5] In a dissolution proceeding subject to de novo review,
the determination of the weight that should be given expert tes-
timony is uniquely the province of the fact finder. 14 The same
is true of lay testimony.
[6] Appellate courts do not generally consider arguments
and theories raised for the first time on appeal. 15
ANALYSIS
Fictitious Cases and Quotations
in Jason’s Brief
This matter presents a novel issue for Nebraska courts: the
use of fictitious, potentially AI-generated cases, holdings, and
quotations. In both his motion to file a corrected brief and at
oral argument, Jason’s counsel asserted that AI was not used
in the drafting of the filed appellate brief. Instead, Jason’s
counsel attributed the fictitious cases and quotations in his
brief to a screen crack on his laptop and his filing the wrong
draft of the brief. Regardless of whether AI was used in the
preparation of Jason’s appellate brief, our analysis in this case
is ultimately the same.
The use of generative AI has been growing over the past
few years and, if used with “caution and humility,” can pro-
vide benefits to professionals who use it. 16 Unfortunately, the
unchecked use of generative AI also leads to court filings
that contain realistic but misleading citations and legal asser-
tions that are either entirely made up or from a real source
that does not contain the purported language cited. 17 These
14 Seemann v. Seemann, 316 Neb. 671, 6 N.W.3d 502 (2024).
15 Simons v. Simons, supra note 5.
16 John G. Roberts, Jr., 2023 Year-End Report on the Federal Judiciary at
5 (Dec. 31, 2023) (available at https://www.supremecourt.gov/publicinfo/
year-end/2023year-endreport.pdf) (last visited Mar. 13, 2026).
17 See Ralph Artigliere, AI Hallucinations in Court: A Wake-Up Call for
the Legal Profession, JD Supra (Jan. 22, 2025), https://www.jdsupra.com/
legalnews/ai-hallucinations-in-court-a-wake-up-4503661/ (last visited Mar.
13, 2026).

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PROSOSKI v. REGAN
Cite as 321 Neb. 38
outputs are often referred to as “hallucinations.” 18 Submission
of these hallucinations creates serious issues. Dealing with
hallucinations in court filings wastes an opposing party’s time
and money, wastes the court’s time and resources, and causes
reputational harms to the legal system. 19 As one court recog-
nized, “Technological advances are commonplace and there
is nothing inherently improper about using a reliable [AI]
tool for assistance. But existing rules impose a gatekeeping
role on attorneys to ensure the accuracy of their filings.” 20
We hold that the submission of fictitious authority to a court,
whether through generative AI or not, can be resolved by
application of our existing rules of professional conduct and
court rules. 21
An attorney’s duty of candor toward a tribunal is described
by Neb. Ct. R. of Prof. Cond. § 3-503.3(a)(1) (rev. 2016),
which states that a lawyer shall not knowingly “make a false
statement of fact or law to a tribunal or fail to correct a
false statement of material fact or law previously made to the
tribunal by the lawyer.” This duty of candor toward the tribu-
nal seeks to avoid conduct by attorneys that undermines the
integrity of the adjudicative process. Under § 3-503.3, com-
ment 2, “the lawyer must not allow the tribunal to be misled
by false statements of law or fact or evidence that the lawyer
knows to be false.”
We have applied this duty of candor in disciplinary pro-
ceedings when an attorney has made false statements in
court pleadings, 22 misrepresented a parenting plan as being
18 See id.
19 See id.
20 Mata v. Avianca, Inc., 678 F. Supp. 3d 443, 448 (S.D.N.Y. 2023).
21 See, e.g., id. (sanctioning attorneys under Fed. R. Civ. P. 11 for submitting
fictitious legal authority, in violation of court rules and New York’s rules
of professional conduct).
22 See State ex rel. Counsel for Dis. v. Pearson, 310 Neb. 256, 965 N.W.2d
28 (2021).

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approved by both parties, 23 and made repeated misrepre-
sentations of fact to opposing counsel and the district court
concerning authority to settle a case. 24 Courts in other juris-
dictions have applied similar rules of candor toward the
tribunal in cases concerning the submission of fictitious
legal authority. 25
Under our rules of professional conduct, an attorney also
has an ongoing duty to provide competent representation. 26
Specifically, § 3-501.1 provides that competent representation
“requires the legal knowledge, skill, thoroughness, prepara-
tion and judgment reasonably necessary for the representa-
tion.” Comment 6 to § 3-501.1 explains that keeping “abreast
of changes in the law and its practice, including the benefits
and risks associated with relevant technology,” is part of pro-
viding competent representation. Similarly, under Neb. Ct.
R. of Prof. Cond. § 3-501.3, an attorney must also act with
reasonable diligence in representing a client.
Further, under Neb. Ct. R. of Prof. Cond. § 3-503.1, an
attorney must avoid asserting a claim or contention that is not
grounded on a nonfrivolous basis. Comment 2 to § 3-503.1
states a position is frivolous if it is not grounded in a good
faith argument for an extension, modification, or reversal of
existing law. As another court has explained, “A fake opinion
is not ‘existing law’ and citation to a fake opinion does not
provide a non-frivolous ground for extending, modifying, or
reversing existing law, or for establishing new law.” 27
23 See State ex rel. Counsel for Dis. v. Schmidt, 303 Neb. 755, 930 N.W.2d
577 (2019).
24 See State ex rel. Counsel for Dis. v. Bouda, 278 Neb. 380, 770 N.W.2d 648
(2009).
25 See, e.g., U.S. v. Hayes, 763 F. Supp. 3d 1054 (E.D. Cal. 2025); Mata v.
Avianca, Inc., supra note 20.
26 See Neb. Ct. R. of Prof. Cond. § 3-501.1 (rev. 2017).
27 Mata v. Avianca, Inc., supra note 20, 678 F. Supp. 3d at 461.

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[7] Finally, under Neb. Ct. R. of Prof. Cond. § 3-508.4(c)
(rev. 2016), an attorney engages in professional misconduct
when they “engage in conduct involving dishonesty, fraud,
deceit or misrepresentation.” This court has held that proof
of actual intent to deceive or defraud is not required to dem-
onstrate an attorney engaged in conduct involving dishonesty,
fraud, deceit, or misrepresentation. 28 Instead, the focus of the
inquiry is on the effect of the lawyer’s conduct. 29
[8] Every attorney admitted to practice in the State of
Nebraska is subject to the exclusive disciplinary jurisdiction
of this court. 30 Acts or omissions by members of the Nebraska
bar which violate the Nebraska Rules of Professional Conduct
are grounds for discipline. 31 Here, Jason’s counsel’s con-
duct of submitting a brief filled with fictitious cases, ficti-
tious quotations, fictitious holdings, and fictitious quotations
from statutes and court rules certainly raises potential viola-
tions of the Nebraska Rules of Professional Conduct, as set
forth above.
Jason’s counsel made numerous false statements of law
throughout the brief. Exercising due diligence—a simple search
of Westlaw and LexisNexis legal databases, the Nebraska
Revised Statutes, Nebraska Supreme Court rules, or the free
Nebraska Appellate Courts Online Library—would have made
clear to Jason’s counsel that any number of the fictitious quo-
tations, from cases and statutes alike, did not exist, that the
“Kennedy v. Kennedy” case relied upon is not a real case,
and that the purported holdings of the real cases cited did not
match the actual holdings of those cases.
28 State ex rel. Counsel for Dis. v. Hanson, 305 Neb. 566, 941 N.W.2d 193
(2020).
29 Id.
30 See Neb. Ct. R. § 3-301 (rev. 2025).
31 See Neb. Ct. R. § 3-303(B). See, also, State ex rel. Counsel for Dis. v.
Glass, 320 Neb. 201, 26 N.W.3d 538 (2025).

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While it is unclear whether Jason’s counsel made these
false statements of law “knowingly,” per § 3-503.3, we agree
with those courts that have found conscious avoidance 32 or
failing to adequately review a brief and verify that the law
presented is good law 33 satisfies the “knowingly” requirement
of the duty of candor toward the tribunal. Even if initial sub-
mission of the fictitious authority was not done “knowingly,”
counsel failed to attempt to correct the false statements of law
until after being made aware by Jennifer’s motion to strike
Jason’s brief and dismiss Jason’s appeal. At oral argument,
Jason’s counsel conceded, only after being pressed by ques-
tioning from the bench, that the authority cited in his brief
was not properly grounded in Nebraska law, despite his pre-
vious assertion to the contrary in his motion for leave to file
a corrected brief. This demonstrated a failure of his duty of
candor toward this court.
Jason’s counsel’s submission of a brief with numerous ficti-
tious citations and quotations is a serious dereliction of coun-
sel’s duty to serve as an officer of the court. “Citing nonexistent
case law or misrepresenting the holdings of a case is making a
false statement to a court. It does not matter if [generative AI]
told you so.” 34 Supporting arguments in such a manner is cer-
tainly “so wholly without merit as to be ridiculous.” 35 We refer
Jason’s counsel to the Counsel for Discipline to investigate the
filing of Jason’s appellate brief rife with fictitious and misrep-
resented authority. 36
32 See Mata v. Avianca, Inc., supra note 20.
33 See Davis v. Marion Cnty. Superior Ct. Juv. Det. Ctr., No. 1:24-cv-01918-
JRD-MJD, 2025 WL 2502308 (S.D. Ind. Sept. 2, 2025).
34 Maura R. Grossman et al., Is disclosure and certification of the use of
generative AI really necessary?, 107 Judicature 68, 75 (2023).
35 White v. White, 320 Neb. 256, 276, 26 N.W.3d 924, 939 (2025).
36 See § 3-303(B). See, also, State ex rel. Counsel for Dis. v. Glass, supra
note 31.

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Jason’s counsel’s explanation that his citations were “sloppy”
due to “copying and pasting . . . from Westlaw” could apply to
a handful of citations where the reporter information is slightly
off but cannot explain the numerous fictitious quotations,
which cannot be located either in the cases they are purported
to be from or in the larger Nebraska jurisprudence. It also does
not explain how a few cases appear to be made up entirely.
Jason’s counsel’s assertion that he simply filed the wrong draft
of the appellate brief lacks credibility.
In short, Jason’s appeal is entirely meritless because it is
not grounded on proper legal foundations when the support-
ing brief is riddled with fabricated citations and quotations.
However, in fairness to Jason, we exercise our discretion to
review his assignment of error for plain error. In doing so, we
find no plain error exists.
We now turn to the question of what sanction is warranted
in this matter. Due to the widespread nature of the fictitious
authority and application in Jason’s brief, we, pursuant to our
inherent authority, order Jason’s appellate brief stricken and his
appeal dismissed. 37 We find these sanctions to be appropriate
in this case to address the issue of Jason’s counsel’s submitting
fictitious authority and to protect the integrity of the judicial
process. This finding, however, does not preclude Jennifer
from filing for an award of attorney fees.
We caution attorneys and self-represented litigants alike
to take care to verify the truth and accuracy of their filings.
Whether using AI or not, the obligations of candor, compe-
tency, diligence, and making good faith arguments remain
the same. AI, like other technological tools, can be a benefit
to the legal community, but it must be used with caution and
humility. Anything less imperils the reputation of the legal
profession and wastes time and resources of both the courts
and litigants.
37 See, e.g., Pillay v. I.N.S., 45 F.3d 14 (2d Cir. 1995) (appellate court has
inherent authority to dismiss appeal as frivolous).

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Jennifer’s Cross-Appeal
On cross-appeal, Jennifer does not contest 2016 as the date
of separation for purposes of property division but argues
the court erred by failing to award her an equalization pay-
ment of $44,117 to account for the alleged marital interest
in their respective real estate because “each party paid down
their mortgages during the marriage.” 38
Focusing on Jason’s duplex that he purchased for approxi-
mately $143,000 in 2005, Jennifer asserts that, under Stava
v. Stava, 39 a marital interest in Jason’s duplex was created
through these mortgage payments. There was no evidence at
trial of the initial amount of the mortgage or of the amount
of any mortgage payments or principal balances before 2023.
Nevertheless, Jennifer points out it was generally Jason’s
burden to show the property was nonmarital. 40 Thus, she
believes the district court erred by failing to use her $169,012
estimation of the duplex’s value in 2016 when they separated,
minus the 2023 mortgage balance of $97,279.36, to find a
$71,732.64 marital interest in the otherwise separate property.
We disagree.
Equitable property division under Neb. Rev. Stat. § 42-365
(Reissue 2016) is a three-step process. 41 Jennifer’s cross-appeal
involves the first step, which is to classify the parties’ property
as marital or nonmarital. 42 The burden of proof rests with the
party claiming that the property is nonmarital. 43 The manner
and method of acquisition involve questions of fact, which
we review de novo on the record, but the classification of the
38 Brief for appellee on cross-appeal at 37.
39 Stava v. Stava, supra note 11.
40 See id.
41 Id.
42 See id.
43 Id.

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property under those facts is a legal question and not a matter
of the court’s discretion. 44
[9-11] Any given property can constitute a mixture of mari-
tal and nonmarital interests; a portion of an asset can be
marital property while another portion can be separate proper-
ty. 45 Appreciation, be it active or passive, in the marital inter-
est is always marital; it is simply part of the marital property. 46
In contrast, property that a party brings into the marriage is
usually excluded from the marital estate. 47 Premarital equity
in real property is a nonmarital asset which, if established,
should be set aside as separate property. 48 This includes its
passive appreciation. 49
In Stava, we adopted the “source of funds” rule that
acquisition of encumbered property only occurs when and
to the extent it becomes unencumbered, including by paying
off the principal of an encumbering loan. 50 In other words,
“acquisition” of property in the first instance can be an
ongoing process and occurs only as it is paid for, because
the value of property is the equity and not the mere legal
title. 51 The use of marital funds to pay down the mortgage
on what was initially separate property acquires the property
during the marriage to the extent the principal is paid, creat-
ing a proportionate marital interest in that property. 52 When
acquisition occurs via payments on the principal of encum-
bering debt, the marital estate receives not just a refund of
44 Id.
45 Id.
46 Id.
47 Id.
48 See id.
49 Id.
50 See id.
51 See id.
52 Id.

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the monetary contribution toward the principal of the loan,
but also a fair return on its investment, which includes pas-
sive appreciation. 53
We set forth in Stava a mathematical formula that can be
utilized to determine the marital interest in a property that
has passively appreciated during a marriage where marital
funds have contributed to its equity. The formula is based
on a percentage interest derived from the portion of equity
acquired through mortgage payments made from marital funds
versus nonmarital funds. It requires the value of the property
at the time of division, the amount of the marital contribution
toward the equity, and the total contribution toward the equity
from both marital and nonmarital funds.
The facts presented in Stava affirmatively established both
that marital funds were used to pay down the principal bal-
ances of encumbering debts on the subject properties and
that the properties acquired before the marriage had passively
appreciated during the marriage. There was also evidence of
the exact amounts of the marital and nonmarital contributions
toward the equity in the subject properties. Finally, in Stava, a
certified appraiser provided valuations of the properties.
In contrast, here there was conflicting lay testimony as to
whether the duplex had appreciated at all during the relevant
time and as to what its value was in 2016. Moreover, while
there was evidence of the existence of a first mortgage on the
duplex, and its balance in 2023, there was no evidence as to
when the mortgage was incurred or in what amount. While
the parties vaguely indicated they each paid their respective
mortgages, even if we presume this insufficient to overcome a
presumption that those payments were with marital funds, there
was no evidence of what amounts, if any, were paid toward the
principal during that time.
In Stava, we recognized the district court has discretion in
applying the source of funds rule and that the mathematical
53 Id.

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formulas set forth therein may not be the only method of
applying the source of funds rule in every situation. But we
find little support for the calculation that Jennifer suggests,
which simply subtracts the 2023 first mortgage debt from her
nonprofessional estimation of the duplex’s 2016 value.
[12] While the burden of proof rests with the party claiming
that the property is nonmarital, 54 Jason established he owned
the duplex before the marriage. Indeed, he established he
owned it approximately 7 years before the marriage in 2012
and another 7 years after their separation in 2016. In contrast,
the parties were only together for 3 years, and there was no
evidence that marital contributions reduced the principal bal-
ance of any encumbering loan during that 3-year period. It
would be mere speculation to calculate any marital interest in
Jason’s duplex without evidence of amounts that the marital
versus nonmarital funds contributed to its equity. Under the
facts presented at trial, it would be mere speculation to even
try to calculate a refund amount corresponding to marital pay-
ments toward the principal of Jason’s duplex.
[13] A fact finder cannot reach conclusions based on guess,
speculation, or conjecture, because conjecture, speculation, or
choice of quantitative possibilities are, of course, not proof. 55
We are mindful that the mortgage information may have been
in Jason’s possession or under his control. However, Jennifer
did not seek enforcement or sanctions below in relation to her
request to produce, and she does not raise any error on appeal
with respect to discovery. 56 Moreover, even under Jennifer’s
calculations, the court’s distribution of the alleged marital
interest in the parties’ respective real estate would not rise to
the level of an abuse of discretion. Under these facts, we will
not reverse the district court’s determination that both proper-
ties were nonmarital.
54 Id.
55 Estate of Block v. Estate of Becker, 313 Neb. 818, 986 N.W.2d 726 (2023).
56 See Simons v. Simons, supra note 5.

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CONCLUSION
As a result of Jason’s appellate brief’s containing numerous
fake and misleading citations, his counsel will be referred to
the Counsel for Discipline for violation of the duty of candor
to the tribunal, his brief is stricken, and his appeal is dismissed.
On Jennifer’s cross-appeal, we find no error in the district
court’s order and affirm the decree of dissolution.
Affirmed in part, and in part dismissed.
Vaughn, J., not participating.
Stacy, J., concurring.
This appeal marks our first opportunity to consider how
courts should respond when a party files a brief that is riddled
with fictitious case citations, fabricated quotes, and arguments
that materially misstate the controlling legal authority. Whether
such a brief is filed by a lawyer or by a self-represented liti-
gant, it is obvious that any attempt to persuade a court or to
oppose an adversary by relying on fabricated legal authority is
an abuse of the judicial system, 1 and such conduct may war-
rant the imposition of appropriate sanctions under a court’s
inherent authority. 2
A review of the evolving case law in this area indicates
that courts in other jurisdictions have imposed a variety of
sanctions against lawyers and selfrepresented parties whose
filings contain fabricated legal authority, including ordering
monetary sanctions to be paid by the responsible attorney
1 See, Park v. Kim, 91 F.4th 610 (2d Cir. 2024); Mata v. Avianca, Inc., 678
F. Supp. 3d 443 (S.D.N.Y. 2023).
2 See Fletcher v. Experian Information Solutions, Incorporated, No.
2520086, 2026 WL 456842 (5th Cir. Feb. 18, 2026) (observing that courts
have inherent power to impose sanctions for abusing judicial process by
filing brief containing fabricated cases and quotes). See, generally, Houser
v. American Paving Asphalt, 299 Neb. 1, 15, 907 N.W.2d 16, 26 (2018)
(recognizing “Nebraska courts, through their inherent judicial power, have
the authority to do all things reasonably necessary for the proper adminis-
tration of justice”).

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or party, 3 ordering reasonable attorney fees to be paid to the
opposing party, 4 ordering the relevant filing or brief to be
stricken, 5 or ordering the party’s appeal to be dismissed. 6
And when the professional conduct of an attorney is called
into question because he or she filed documents that contain
fabricated legal authority, courts routinely refer the matter to
the relevant disciplinary body for investigation of possible
ethical violations. 7
Here, the appellant’s counsel received fair notice, well in
advance of oral argument, that the brief he filed on behalf of
his client contained a staggering number of fictitious citations,
fabricated quotes, and misleading propositions and arguments.
And during oral argument, counsel was given a meaningful
opportunity to explain how and why that occurred and to show
good cause why sanctions should not be imposed. Because
counsel provided no plausible good faith explanation for the
3 See, Fletcher, supra note 2 (ordering attorney to pay sanction of $2,500
for including quotations, citations, and assertions in brief not supported
by case law); Wadsworth v. Walmart Inc., 348 F.R.D. 489 (D. Wyo. 2025)
(ordering sanctions against plaintiffs’ attorneys for citing fake cases);
Mata, supra note 1 (imposing $5,000 sanction against attorneys and law
firm for citing multiple nonexistent cases in brief and submitting fabri-
cated excerpts from nonexistent cases to court).
4 See, In re Kheir, 674 B.R. 631 (S.D. Tex. 2025) (ordering attorney to pay
opposing party attorney fees and court costs for citing nonexistent cases);
In re Kenney, 422 So. 3d 905 (La. App. 2025) (same); Kruse v. Karlen,
692 S.W.3d 43 (Mo. App. 2024) (sanctioning pro se party $10,000 in attor-
ney fees where party submitted 22 fictitious citations in brief).
5 See, Grant v. City of Long Beach, 96 F.4th 1255 (9th Cir. 2024) (striking
appellant’s brief citing nonexistent cases and misrepresenting holdings
of cases); Matter of Samuel, 82 Misc. 3d 616, 206 N.Y.S.3d 888 (2024)
(striking pleading citing five nonexistent cases).
6 See, Grant, supra note 5 (striking brief with fictitious cases and dismiss-
ing appeal); Kruse, supra note 4.
7 See, Park, supra note 1; Johnson v. Dunn, 792 F. Supp. 3d 1241 (N.D.
Ala. 2025). See, also, Dehghani v. Castro, 782 F. Supp. 3d 1051 (D.N.M.
2025) (ordering counsel to selfreport to state bar’s disciplinary board for
filing brief containing nonexistent cases).

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extensive fabrications in the brief that he signed and filed, I
agree with the majority that this court has the inherent author-
ity to strike the appellant’s brief in its entirety 8 and that we
should do so.
I also agree that to ensure the protection of the public,
this court has an obligation to report counsel conduct to the
Counsel for Discipline of the Nebraska Supreme Court so
that possible violations of the Nebraska Rules of Professional
Conduct can be thoroughly investigated and any appropri-
ate disciplinary action commenced. 9 And I do not understand
anything in the majority’s opinion to have prejudged either the
scope or outcome of the attorney disciplinary process. Instead,
in the appeal before us for review, this court has merely exer-
cised its inherent authority, sua sponte, to impose appropriate
and measured sanctions in response to the filing of an appellate
brief that was rife with fabricated legal authority, that failed to
comply with the appellate briefing rules, 10 and that threatened
to undermine the integrity of the appellate process.
Finally, although I agree completely with the majority’s
decision in this case to review the record for plain error
and with its conclusion that no plain error exists, I think
the proper disposition under such circumstances is to affirm
the judgment of the district court, rather than to dismiss the
appeal. Once we struck the appellant’s brief as a sanction, we
8 See, e.g., Kellogg v. Mathiesen, 320 Neb. 223, 26 N.W.3d 651 (2025)
(stating rule that when appellant’s brief fails to comply with court rules,
appellate court either may proceed as though party failed to file brief and
provide no review at all or may examine proceedings for plain error);
Houser, supra note 2. See, also, Neb. Ct. R. App. P. § 2-109(D)(1)(e), (f),
and (g) (rev. 2025) (requiring briefs to concisely state each alleged error,
include “the legal propositions urged as controlling,” and argue each error
using relevant propositions of law and legal authority); Neb. Ct. R. App.
P. § 2-110(A) (rev. 2022) (providing if appellant fails to file brief, appeal
is subject to dismissal).
9 See Neb. Rev. Code of Judicial Conduct § 5-302.15(B) and (D).
10 See §§ 2-109(D) and 2-110(A).

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undoubtedly had the authority, under both our inherent power
and the appellate court rules, to dismiss this appeal without
conducting any review at all. But since we exercised our dis-
cretion to examine the record for plain error and found none,
we necessarily engaged in appellate review. I therefore think
affirmance is the more appropriate disposition, but I acknowl-
edge the practical reality that the outcome is the same whether
the judgment is affirmed or the appeal is dismissed. 11
11 See In re Estate of Marsh, 145 Neb. 559, 17 N.W.2d 471 (1945) (recogniz-
ing general rule that dismissal of appeal without examining merits oper-
ates as affirmance of judgment appealed).