Brown v. Fisher-Price, Inc.

IN THE SUPERIOR COURT OF THE STATE OF DELAWARE

AMEENA BROWN and EVAN )
BRAGGS, Individually and as Co- )
Administrators of the Estate of A.B., )
deceased, )
Plaintiffs, )
)
v. ) C.A. No. N20C-01-067 PAW
)
FISHER-PRICE, INC. and )
MATTEL, INC. )
)
Defendants. )

Submitted: November 8, 2024
Decided: December 20, 2024

MEMORANDUM OPINION AND ORDER

Upon Consideration of Defendants’ Motion to Exclude the Testimony of Plaintiffs’
Expert Dennis Rosen, M.D. Pursuant to D.R.E. 702;

DENIED, in part, and GRANTED, in part.

Robert J. Leoni, Esq., Shelsby & Leoni, PA, Attorney for Plaintiffs.

Jennifer C. Wasson, Esq., Carla M. Jones, Esq., and Ryan Kingshill, Esq., of Potter
Anderson & Corroon LLP, Attorneys for Defendants.

WINSTON, J.
I. INTRODUCTION1

Defendants move to exclude the expert testimony of Dr. Dennis Rosen under

Delaware Rule of Evidence 702.2 Plaintiffs seek to introduce Rosen’s testimony to

show the RnP places infants in an anatomically unsafe position.3 Rosen also intends

to testify the RnP in the instant case allowed for an infant, A.B., to roll onto his side

and press his face against the side of the RnP, ultimately resulting in A.B.’s death.4

Rosen’s report also touches on the topic of rebreathing.5 Defendants contend: (1)

Rosen lacks a scientifically reliable basis to offer any general or specific causation

opinion; (2) Rosen’s reliance on Mannen’s report renders Rosen’s opinion

inadmissible; (3) Rosen’s opinion as to A.B.’s cause of death “rests on Dr. Rosen’s

complete guesswork;” (4) Rosen utilized a flawed differential diagnosis

methodology; and (5) Rosen based his opinion on a theory of increased risk that

Pennsylvania law precludes.6

1
This Memorandum Opinion and Order references the factual and procedural
background outlined in the Court’s Memorandum Opinion and Order upon
Consideration of Defendants’ Motion for Summary Judgment, which the Court
incorporates by reference. Unless otherwise noted, defined terms are ascribed the
same meaning as in the Court’s Summary Judgment Memorandum Opinion.
2
Defs.’ Mot. to Exclude Pls.’ Expert Dennis Rosen, M.D., D.I. 177.
3
Pls.’ Opp’n to Defs.’ Mot. to Exclude Dennis Rosen, M.D., D.I. 205.
4
Id.
5
D.I. 178 Pls. Ex. F at 8-10, 16-22 (“Dr. Rosen’s Report”); Rosen’s testimony
regarding rebreathing is examined in a separate Memorandum Opinion and Order.
6
D.I. 177.
2
II. STANDARD OF REVIEW

Delaware Rule of Evidence (“D.R.E.”) 702 governs the admission of expert

testimony. Under D.R.E. 702, expert opinion testimony is admissible provided that

the witness “is qualified as an expert by knowledge, skill, experience, training, or

education” if:

(a) the expert’s scientific, technical, or other
specialized knowledge will help the trier of the fact to
understand the evidence or to determine a fact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles
and methods; and
(d) the expert has applied the principles and methods to
the facts of the case.7

The burden falls on the party seeking to admit the expert testimony to show,

by a preponderance of the evidence, its admissibility under D.R.E. 702.8 “Once

expert testimony is challenged, the reviewing court must ensure that the proffered

testimony is both relevant and reliable.”9 To fulfill this duty, this Court acts as

gatekeeper, determining if “the reasoning or methodology underlying the testimony

is scientifically valid and … whether that reasoning or methodology properly can be

7
D.R.E. 702.
8
Bowen v. E.I. DuPont de Nemours & Co., Inc., 906 A.2d 787, 795 (Del. 2006).
9
Scottoline v. Women First, LLC, 2023 WL 2325701 at *3 (Del. Super. Mar. 1, 2023)
(citing Daubert v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579, 597 (1993)).
3
applied to the facts in issue.”10 In making that determination, the Court applies a

five-step test that examines whether:

(1) the witness is qualified as an expert by knowledge,
skill, experience, training[,] or education; (2) the evidence
is relevant [and reliable]; (3) the expert’s opinion is based
upon information reasonably relied upon by experts in the
particular field; (4) the expert will assist the trier of fact to
understand the evidence or to determine a fact in issue; and
(5) the expert testimony will not create unfair prejudice or
confuse or mislead the jury.11

For scientific evidence to be deemed reliable, the testimony must be rooted in

science and derived from the scientific method.12 Expert testimony is relevant when

it assists the trier of fact to understand the evidence or determining a fact in issue.

Thus, the core of a Daubert analysis is the “principles and methodology” used in

formulating an expert’s testimony, not on the expert’s resultant conclusions.13 This

Court possesses “broad latitude to determine whether any or all of the Daubert

Gen. Motors Corp. v. Grenier, 981 A.2d 531, 536 (Del. 2009) (internal quotations
10

omitted) (quoting Daubert, 509 U.S. at 592-93).
11
Norman v. All About Women, P.A., 193 A.3d 726, 729-30 (quoting Smith v. Grief,
2015 WL 128004 (Del. Jan. 8, 2015)).
12
Daubert, 509 U.S. at 590-94.
13
Bowen, 906 A.2d at 794 (citing Daubert, 509 U.S. at 595).
4
factors are reasonable measures of reliability in a particular case.”14 “A strong

preference exists for admitting evidence that may assist the trier of fact.”15

III. ANALYSIS

Rosen devotes a material amount of his report to a more general overview of

why inclined sleepers are unsafe according to the American Academy of Pediatrics

(the “AAP”).16 He then utilized a differential diagnosis, ruling out other potential

causes of death and concluding the RnP’s design allowed A.B. to roll onto his side.17

Rosen opines that once A.B. rolled to his side his face pressed against the side of the

RnP, resulting in A.B.’s death.18 Rosen based his opinion on his experience as a

pediatric pulmonologist, his review of A.B.’s medical records, the witness

14
Grenier, 981 A.2d at 536 (internal quotations omitted) (quoting Kumho Tire Co.,
Ltd. v. Carmichael, 526 U.S. 137, 141 (1999)).
15
Norman, 193 A.3d at 730.
16
Dr. Rosen’s Report.
17
Id. at 24-26.
18
Id. at 26.
5
statements of A.B.’s mother and grandmother,19 and several studies and publications

cited throughout Rosen’s opinion.20

A. ROSEN QUALIFIES AS AN EXPERT IN PEDIATRIC PULMONOLOGY.21

Defendants assert Rosen lacks a sufficient background in biomechanics,

particularly as applied to an inclined sleeper, and thus cannot offer a causation

opinion that relies on biomechanics or engineering.22 Defendants further note Rosen

did not train as a forensic pathologist, focusing his practice on “sleep-disordered

breathing in infants and children with underlying medical complexity.”23 As Rosen’s

opinion relies, at least in part, on an understanding of biomechanics and forensic

19
At oral argument, Defendants contended that all Plaintiffs’ expert opinions were
factually flawed because they failed to correctly account for the position of A.B.’s
face as described by his mother in her deposition. This assertion is incorrect. See
Dr. Calhoun’s Report at 6; Dr. Hoffman’s Report at 6; Dr. Mannen’s Report at 5; Dr.
Rosen’s Report at 6; Dr. Ross’ Report at 4. Further, challenges to the factual basis
of an expert opinion go to credibility, not admissibility. An expert’s testimony will
be excluded on the factual basis grounds only in the narrow circumstance where the
expert has completely neglected the core facts of the case. See Henlopen Hotels,
Inc. v. United National Insurance Co., 2020 WL 233333 (Del. Super. Jan. 15, 2020).
This is not the case here.
20
Id. at 1-2.
21
Defendants’ arguments for excluding the testimony of Rosen are almost identical
to their arguments for excluding Hoffman’s testimony.
22
D.I. 177 at 12.
23
Id.
6
pathology, Defendants posit he lacks the requisite expertise to give such an

opinion.24

A review of Rosen’s report reveals he does rely upon biomechanical

conclusions in constructing his opinion.25 Biomechanics, however, make up just a

portion of Rosen’s report. Rosen also considers literature from the AAP,26 the

medical examiner’s report,27 a differential diagnosis,28 and Rosen’s own experience

and training. Rosen’s opinion does not rely primarily on biomechanical concepts.

His reliance on biomechanical conclusions does not preclude him from qualifying

as an expert in pediatric pulmonology, and his expertise as a pediatric pulmonologist

forms the backbone of his opinion and conclusions.29 Rosen’s training, education,

and experience qualify him as an expert on pediatric pulmonology and infant sleep

disorders.

24
Id. at 19.
25
Dr. Rosen’s Report at 19-21.
26
Id. at 16.
27
Id. at 22.
28
Id. at 24-24.
29
See Lee v. Holbrook, 2021 WL 5492666 at *3 (Del. Super. Nov. 22, 2021) (noting
that a medical expert relied upon a biomedical expert’s conclusions in forming his
own expert opinion).
7
B. ROSEN MAY RELY ON MANNEN’S REPORT AND STUDIES TO SUPPORT HIS
OPINION.

Rosen cites to several studies and reports, including the expert report prepared

by Mannen.30 Defendants argue Rosen’s reliance on Mannen’s report renders

Rosen’s opinion inadmissible. Specifically, they contend that Mannen’s report: (1)

should be inadmissible, (2) does not support Rosen’s conclusion, and (3) lacks the

requisite fit to be applicable to this case.31

Defendants filed a separate motion regarding the admissibility of Mannen’s

expert testimony, but the admissibility of her testimony does not materially affect

the analysis of Rosen’s opinion.32 Under D.R.E. 703, an expert may base their

opinion on inadmissible evidence as long as “experts in the particular field would

reasonably rely on those kinds of facts or data in forming an opinion on the subject

…” Thus, the analysis must center on whether Mannen’s reports and publications

are the kind a pediatrician would reasonably rely upon.33

30
Dr. Rosen’s Report at 19-20.
31
D.I. 177 at 15.
32
This analysis is identical to the analysis in the Memorandum Opinion and Order
discussing the admissibility of Hoffman’s testimony.
33
D.R.E. 703; see also Norman, 193 A.3d at 730.
8
Rosen primarily relies on Mannen’s Biomechanical Engineering Report,34 as

well as two studies Mannen co-authored.35 Defendants assert all of Mannen’s work

cited by Rosen cannot be applied to the facts of the instant case.36 Defendants posit

for any biomechanical study to be relevant to the facts of this case those studies must

have been conducted with infants fully swaddled.37

D.R.E. 702 requires that expert testimony “help the trier of fact to understand

the evidence or to determine a fact in issue.” “[A]n expert’s methodology must be

not only reliable intrinsically but also be reliably applied to the facts of the specific

case …”38 Defendants characterize this concept as requiring any study relied upon

by an expert to have occurred under near-identical circumstances to the facts of the

instant case.39 This contention is addressed in the Court’s Memorandum Opinion

and Order regarding the testimony of Mannen.

Defendants characterize Rosen’s reliance on other expert reports as turning

Rosen into “merely a conduit for other third-party reports, articles, and

34
Dr. Rosen’s Report at 19.
35
Id. at 20.
36
D.I. 177 at 14.
37
Id. at 16.
38
Grenier, 981 A.2d at 529.
39
D.I. 177 at 16.
9
investigations ...”40 An expert witness can however, “rely upon the records of

another expert in formulating his own opinion.”41 Regarding Rosen’s reliance on

Mannen’s publications, he primarily uses them to provide context as to why Rosen

believes inclined sleepers are dangerous, and how an infant placed in a supine

position may be able to roll to their side more easily in an inclined environment.42

Rosen applies his own expertise to the facts of this case. His reference to

Mannen’s report does not serve as merely a recitation of Mannen’s findings.43

Likewise, the study Rosen cites to is from a reputable source and adds context to his

determination that A.B. rolled onto his side before dying.44 Mannen’s publications

prepared in advance of this litigation are the type of source an expert in pediatric

sleep disorders would reasonably rely upon.

C. ROSEN’S OPINION ON THE CHAIN OF EVENTS LEADING TO A.B.’S
DEATH FOLLOWS LOGICALLY FROM ROSEN’S CONCLUSIONS AND DOES
NOT RENDER HIS OPINION INADMISSIBLE.

Defendants contend Rosen’s opinion as to A.B.’s cause of death “rests on Dr.

Rosen’s complete guesswork as to what happened on the night of the infant’s

40
D.I. 177 at 3.
41
Stewart v. Dep’t of Servs. For Child., Youth, & their Fams., 991 A.2d 750, 758
(Del. 2010).
42
Dr. Rosen’s Report at 19-20.
43
Dr. Rosen’s Report at 19.
44
Dr. Rosen’s Report at 20.
10
death.”45 Defendants argue Rosen cannot possibly know what happened in the hours

between A.B.’s mother placing him in the RnP and A.B.’s death.46 Further,

Defendants note Rosen admits he does not know what position A.B. died in.47

Defendants assert “simply finding the infant on his side has no medical significance

to a causation determination.”48

Rosen’s opinion certainly relies on the facts provided to him regarding A.B.’s

position in the RnP when A.B.’s mother went to sleep, and how A.B.’s mother found

him in the morning.49 He considered those facts in concluding A.B. rolled onto his

side before his death.50 He also considered the medical examiner’s report, including

the lividity marks notated by the medical examiner.51 Then, Rosen makes an

analytical leap in concluding A.B. most likely rolled onto his side based mostly on

A.B.’s last known position before his death, the position A.B. was found in, the

lividity marks, and the differential diagnosis Rosen performed.52

45
D.I. 177 at 3.
46
Id. at 20.
47
Id.
48
Id. at 21.
49
Dr. Rosen’s Report at 23.
50
Id.
51
Id. at 7.
52
Id. at 26.
11
Rosen’s approach to determining A.B.’s cause of death relied upon the facts

present in this case, his training and experience, and logical deductions that follow

reasonably from his earlier conclusions. Thus, the Court finds that Rosen’s opinion

provides enough logical support for that analytical leap.53 Accordingly, the Court

will permit Rosen to testify and allow any alleged shortcomings in his testimony to

be cured by cross examination.

D. ROSEN’S OPINIONS FORMED USING DIFFERENTIAL DIAGNOSIS
METHODOLOGY ARE ADMISSIBLE.

Rosen utilized a differential diagnosis to determine A.B.’s cause of death.54

Defendants argue Rosen used a flawed methodology and did not “engage in a

systematic process of elimination, and he failed to provide a reasoned, scientific

explanation rooted in science in the actual facts of the case to rule out each potential

cause of death.”55 Defendants also posit Rosen failed to consider several viable,

alternative causes of death.56

“A differential diagnosis is deemed reliable for Daubert purposes if it is

rendered after the physician conducts a physical examination, takes a medical

53
See Minner v. American Mortg. & Guar. Co., 791 A.2d 826, 866 (Del. Super. 2000)
(“It is not necessary that an expert report have an undisputed foundation, it need only
be based on valid reasoning and reliable methodology”).
54
Id. at 24-25.
55
D.I. 177 at 27.
56
Id. at 28-30.
12
history, reviews clinical tests, including laboratory tests, and excludes obvious (but

not all) alternative causes.”57 A doctor does not need to utilize all of those techniques

to create a reliable differential diagnosis.58 “For instance, a physician may reach a

reliable differential diagnosis without himself performing a physical examination,

particularly if there are other examination results available.”59 This Court must

“delve into the particular witness’s method of performing a differential diagnosis to

determine if his [ ] ultimate conclusions are reliable.”60 “So long as physicians

employ objective diagnostic techniques when performing a differential diagnosis,

their diagnosis will be reliable under Daubert ...”61 Differential diagnosis can be a

difficult method to test for reliability, with variance from case to case, and requires

the Court to employ a “flexible” analysis regarding admissibility.62

Rosen’s differential diagnosis does not go into great detail as to why he rules

out each alternative cause of death. He reviewed medical records, witness

statements, and the medical examiner’s report. Rosen then noted “there was no

57
State v. McMullen, 900 A.2d 103, 117 (Del. Super. 2006).
58
Id.
59
Id. (internal quotations omitted) (quoting Kannakeril v. Terminix Intern., Inc., 128
F.3d 802, 807 (3d Cir. 1997)).
60
Id. (internal quotations omitted) (quoting Poust v. Huntleigh Healthcare, 998
F.Supp. 478, 496 (D.N.J. 1998)).
61
Id. at 117-18.
62
Id. at 118.
13
evidence” for many of the alternative causes of death he considered.63 Defendants

argue Rosen’s simple conclusion that no evidence supported those potential causes

of death does not provide enough scientific support.64 Defendants do not suggest

evidence exists to support those alternative theories, but rather contend Rosen

needed to provide an expanded explanation as to why he found no evidence to

support those theories.

The Court’s analysis of Rosen’s differential diagnosis requires the Court to

decide if Rosen employed a reliable and objective methodology to ruling out

potential causes of death.65 If a doctor finds no evidence of something, it remains

unclear how exactly they could expand upon that finding. Rosen explains where he

would have seen evidence of each alternative cause of death, and then concludes no

such evidence exists.66 Under the guidance from Delaware law encouraging the

Court to take a flexible approach in determining the admissibility of a differential

diagnosis,67 Defendants have not raised sufficient concerns to justify excluding

Rosen’s differential diagnosis based on his methodology.

63
Dr. Rosen’s Report at 24-25.
64
D.I. 177 at 27.
65
McMullen, 900 A.2d at 117.
66
Dr. Rosen’s Report at 24-25.
67
Id.
14
As to Rosen’s failure to rule out several potential causes of death, several of

the potential causes Defendants posit Rosen failed to consider appear to be addressed

by Rosen. Defendants assert Rosen failed to consider overheating, Sudden Infant

Death Syndrome (“SIDS”), and A.B.’s unique risk factors based on his prematurity

and document medical conditions.68 Rosen explained in his deposition that a SIDS

diagnosis results from an inability to find another plausible explanation.69 It follows

logically that as Rosen concluded A.B. died from asphyxiation, he necessarily would

rule out SIDS because asphyxiation stood as a cause of death Rosen could not

exclude.

Rosen also examined A.B.’s medical history and considered several of A.B.’s

medical conditions as part of his differential diagnosis.70 Rosen noted “[A.B.] was

in his usual state of health in the 24 hours preceding his death.”71 Defendants’

contention that Rosen did not consider A.B.’s medical conditions appears to be

incorrect.

Although Rosen did not consider overheating as a potential cause of death, in

his deposition, he explained he saw no evidence to support a theory based on

68
D.I. 177 at 28.
69
D.I. 205 Pls. Ex. I at 161-62 (“Dr. Rosen’s Deposition”).
70
Dr. Rosen’s Report at 24-25.
71
Id. at 22.
15
overheating.72 “A differential diagnosis is deemed reliable for Daubert purposes if

it ... excludes obvious (but not all) alternative causes.”73 Thus, the Court must

consider whether overheating rates as an obvious alternative cause of death in this

case. Rosen found “no evidence of autonomic dysfunction,” noted the temperature

of the room registered around 70 degrees Fahrenheit, and found that A.B. was

dressed appropriately for that temperature.74 The Court finds Rosen’s explanation

to be supported by the facts and grounded in logic.

Because the Court’s analysis under Daubert leans toward admissibility if the

information may assist the trier of fact, Rosen’s differential diagnosis is admissible.

E. ROSEN CANNOT RELY ON INCREASED RISK OF HARM TO ESTABLISH
CAUSATION.75

Defendants’ final challenge to Rosen’s report centers on Rosen’s

determination that the RnP’s design increases the risk of infant death. 76 Rosen

discusses the increased risk associated with inclined sleepers at length within his

report.77 Defendants argue Rosen’s discussion of increased risk renders his opinion

72
Dr. Rosen’s Deposition at 268.
73
McMullen, 900 A.2d at 117 (emphasis in original).
74
Dr. Rosen’s Deposition at 268.
75
This analysis is almost identical to the analysis in the Memorandum Opinion and
Order discussing the admissibility of Hoffman’s testimony. The key difference is
that Rosen does not otherwise conclude the RnP caused A.B.’s death.
76
D.I. 177 at 24.
77
Dr. Rosen’s Report at 16-22.
16
inadmissible because Pennsylvania courts do not allow testimony regarding

increased risk causation in products liability cases.78

Pennsylvania law does not permit the use of “increased risk” testimony to

establish causation in products liability cases.79 At oral argument, Plaintiffs

acknowledged that increased risk standing alone does not equal causation under

Pennsylvania law because the jury must later decide whether the increased risk was

a substantial factor in achieving causation.80 After extensive argument, Defendants

conceded their position with Plaintiffs as they “understood counsel to be

acknowledging that they were not trying to substitute increased risk for proof of

causation.”81

78
D.I. 177 at 24.
79
See In re Lipitor (Atorvastatin Calcium) Mktg., Sales Pracs. & Prod. Liab. Litig.,
227 F. Supp. 3d 452, 487 n. 28 (D.S.C. 2017), aff'd sub nom. In re Lipitor
(Atorvastatin Calcium) Mktg., Sales Pracs. & Prod. Liab. Litig. (No II) MDL 2502,
892 F.3d 624 (4th Cir. 2018); see also Lempke v. Gen. Elec. Co., 2012 WL 94547 at
*4 (W.D. Pa. Jan. 11, 2012) (finding increased risk as causation only applied to
situations where the defendant has a duty to perform an act, or where defendant
undertook an obligation to perform an act).
80
Pls’ Suppl. Br. at 12; Tr., Oral Argument, C.A. No. N20C-01-067 PAW at 102:23-
104:4. Plaintiffs further clarify that “[t]his increased risk argument is really an
argument to the point of what will the jury instructions look like and what will the
arguments look like to the jury, but it is absolutely a proper basis by which causation
can be proved.” Id. at 107:13-19.
81
Tr., Oral Argument, C.A. No. N20C-01-067 PAW, at 147:7-15.
17
Here, Rosen’s report does opine as to the increased risk caused by the RnP82

and determines A.B. died from asphyxiation.83 However, Rosen’s report does not

appear to opine that the RnP caused A.B.’s death. Moreover, Defendants have

conceded that Plaintiffs are not attempting to substitute increased risk for causation.

Accordingly, Rosen may not testify that increased risk establishes causation.

IV. CONCLUSION

Rosen utilized an admissible differential diagnosis to determine A.B.’s cause

of death. Defendants’ contention that Rosen failed to consider alternative causes of

death is unpersuasive. Rosen’s opinion does not require expertise in biomechanics

or forensic pathology. He relies on reputable and reliable sources, and his

qualifications as a pediatric pulmonologist are unchallenged.

For these reasons, the Court will allow Rosen to testify as an expert witness.

He may not opine as to any increased risk establishing causation.

IT IS SO ORDERED.

/s/ Patricia A. Winston
Patricia A. Winston, Judge

82
Dr. Rosen’s Report at 16-22.
83
Id. at 26.
18