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 Benjamin Hoffman, M.D. Pursuant to D.R.E. 702;

DENIED.

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. Benjamin Hoffman

under Delaware Rule of Evidence 702.2 Plaintiffs seek to introduce Hoffman’s

testimony to show: (1) the use of inclined sleeper products place infants in a

dangerous sleeping position, increasing their risk of Sudden Unexplained Infant

Death Syndrome (“SUIDS”);3 and (2) the use of an inclined sleeper caused the death

of the infant in the instant case, A.B.4 Hoffman’s report also touches on the topic of

rebreathing.5 Defendants contend: (1) Hoffman lacks expertise in biomechanics and

cannot offer biomechanical opinions; (2) Hoffman improperly relies on studies

incomparable to the facts of this case; (3) Hoffman did not utilize reliable

methodologies when constructing his opinion; and (4) Hoffman relies on a theory of

increased risk causation which is impermissible under Pennsylvania law.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 Benjamin Hoffman, M.D., D.I. 168; see also
D.I. 169 (“Defs.’ Ex. F-P”); see also D.I. 170 (“Def.’s Ex. Q”).
3
Pls.’ Opp’n to Defs.’ Mot. to Exclude Benjamin Hoffman, M.D., D.I. 209.
4
Defs.’ Ex. F, D.I. 169, at 18 (“Dr. Hoffman’s Report”).
5
Dr. Hoffman’s Report; Hoffman’s testimony regarding rebreathing is examined in
a separate Memorandum Opinion and Order.
6
D.I. 168 at 2-3.
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

10
Gen. Motors Corp. v. Grenier, 981 A.2d 531, 536 (Del. 2009) (internal quotations
omitted) (quoting Daubert, 509 U.S. 579 at 592-93).
11
Norman v. All About Women, P.A., 193 A.3d 726, 729-30 (quoting Smith v. Grief,
106 A.3d 1050 (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

In his report, Hoffman opines A.B. died from suffocation caused by turning

onto his side.16 Hoffman further opines the design of the RnP “increased the risk of

harm of[,] and was the direct cause of[,] A.B.’s suffocation.”17 Hoffman based his

opinion on his experience as a pediatrician, his review of A.B.’s medical records,

the witness statements of A.B.’s mother,18 and certain studies.19

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. Hoffman’s Report at 19.
17
Id.
18
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.
19
Id.
5
A. HOFFMAN QUALIFIES AS AN EXPERT ON INFANT SLEEP CONDITIONS.

Defendants first argue Hoffman does not qualify as an expert in

biomechanics.20 Defendants posit Hoffman’s testimony “plainly rests on

biomechanics.”21 As Hoffman does not qualify as an expert in biomechanics,

Defendants contend his opinion cannot be admitted as expert testimony.22

A review of Hoffman’s report, and the supplemental letter he submitted in

response to the Defendants’ experts, shows Hoffman based part of his opinion on

the biomechanical setting created by placing an infant in the RnP.23 A significant

portion of his opinion, however, discusses both why the American Academy of

Pediatrics (the “AAP”) discourages the use of inclined sleepers, and how Hoffman

ruled out other possible causes of death by examining A.B.’s records.24 Hoffman

relies on his education and experience as a certified pediatrician, published reports,

and the reports of other experts submitted for this case to render his opinion.

20
D.I. 168 at 11.
21
Id. at 13.
22
Id.
23
Dr. Hoffman’s Report at 2 (“[A.B.]’s death was the result of biomechanical
alterations manifested when …”; “These biomechanical alterations led to [A.B.]
rolling from supine to his left side, leading to suffocation.”).
24
See id. at 7-13 (discussing SUIDS generally, as well as the efforts by the AAP and
the Consumer Product Safety Commission (the “CPSC”) to discourage or ban
inclined sleepers); see also id. at 16-18 (discussing Dr. Hoffman’s methodology for
ruling out other possible causes of A.B.’s death).
6
Although his opinion contains discussions of biomechanical concepts,

Defendants mischaracterize Hoffman’s opinion as biomechanical testimony. As

Defendants noted, “Dr. Hoffman could have used any words or phrases to describe

his opinion, and he chose to frame it explicitly in biomechanical terms …”25

Hoffman could have chosen less technical terms to reach the same conclusions.

Merely using those technical terms does not transform his opinion into one only a

biomechanical expert could render. Hoffman’s training, education, and experience

qualify him as an expert on the safety of infant sleeping conditions.

B. HOFFMAN MAY RELY ON MANNEN’S STUDIES TO SUPPORT HIS
OPINION.

Hoffman bases part of his opinion on the work of another proposed expert

witness, Dr. Erin Mannen.26 Plaintiffs’ contention that Hoffman’s opinion does not

rely on Mannen’s studies in any way runs contrary to the two full pages Hoffman

devotes to discussing Mannen’s findings.27 Defendants argue this reliance

undermines Hoffman’s report because Mannen’s findings lack credibility, do not

support Hoffman’s conclusions, and cannot be applied to the facts of this case.28

25
D.I. 168 at 12.
26
Dr. Hoffman’s Report at 14-16.
27
Id.
28
D.I. 168 at 17-23.
7
Defendants have filed a separate motion challenging the admissibility of

Mannen’s expert testimony, but the admissibility of her testimony does not

materially affect the analysis of Hoffman’s opinion. Even if inadmissible 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 studies and publications are the kind a pediatrician would reasonably rely

upon.29

Hoffman relies on three of Mannen’s studies: (1) a 2019 study commissioned

by the CPSC analyzing inclined sleep products for infants;30 (2) a peer-reviewed

study published in the Journal of Biomechanics in 2020 on inclined sleep surfaces

and infant muscle activity;31 and (3) a peer-reviewed study also published in the

Journal of Biomechanics in 2021 on infant inclined sleep product design.32

Defendants posit the CPSC study cannot be relied upon as it did not undergo peer

29
D.R.E. 703; see also Norman, 193 A.3d at 730.
30
Defs.’ Ex. J, D.I. 169.
31
Defs.’ Ex. K, D.I. 169.
32
Defs.’ Ex. L, D.I. 169.
8
review.33 Whether a study has been subjected to peer review factors into the Court’s

analysis of the reliability of the study.34

Peer review, however, stands as one part of a “flexible inquiry” that also

considers whether the theory in question has been tested, any potential error rate

associated with the study, standards controlling the study, and whether the

underlying reasoning or methodology has attracted widespread acceptance within

the relevant scientific community.35 A study’s lack of peer review does not

necessarily render it unreliable.

Mannen generated the CPSC report in response to a request from the U.S.

government, not an academic publication.36 The CPSC report examined the results

of scientific testing, carefully outlined the methodology used and the associated

limitations, and appears to have at least partially spurred legislative action to recall

products like the RnP.37 Accordingly, the Court finds that the CPSC report authored

by Mannen, despite its lack of peer review, is sufficiently reliable within the relevant

scientific community. Mannen’s CPSC study involved a methodology that attracted

33
D.I. 168 at 15.
34
Daubert, 509 U.S. at 580.
35
Id.
36
Defs.’ Ex. J, D.I. 169.
37
Id.; see also D.I. 209 at 24. Mannen’s CPSC study caused the CPSC to implement
tighter safety regulations for inclined sleepers. D.I. 211 at 2.
9
widespread acceptance in the scientific community and was controlled by CPSC

standards, and, as a result, constitutes the type of information reasonably relied upon

by experts in pediatrics.

The other studies referenced by Hoffman were published in a reputable

biomechanics journal. The two studies were subjected to peer review and

publication, and the methodology within those studies gained acceptance within the

scientific community. The studies were cited in other peer-reviewed work within

scientific journals on early human development, pediatric child health, and public

health.38 Accordingly, Mannen’s other studies constitute the type of information

reasonably relied upon by experts in pediatrics, and Hoffman’s reliance on those

studies does not preclude him from offering his opinion.

Defendants also assert all three of the studies are inapplicable to the instant

case because they cannot be applied to the specific set of facts present in this case.39

As the infant in this case suffered from a medical condition causing tight muscles

38
See Laura R. Sangaré et al., The Risk of Sleep-Related Death in an Inclined Sleep
Environment, 24 BMC PUB. HEALTH 1 (Aug. 12, 2024) (citing Dr. Mannen’s study
from the Journal of Biomechanics in 2020); see also B.C. Galland et al., Prone
Versus Supine Sleep Position: A Review of the Physiological Studies in SIDS
Research, 38 J. PAEDIATRICS & CHILD HEALTH 4, 322 (Aug. 2022) (citing Dr.
Mannen’s study from the Journal of Biomechanics in 2021); see also Danielle N.
Siegel et al., Commercial Infant Products Influence Body Position and Muscle Use,
198 J. EARLY HUMAN DEV. 106122 (Sept. 12, 2024) (citing Dr. Mannen’s study from
the Journal of Biomechanics in 2021).
39
D.I. 168 at 20.
10
and limited range of motion, Defendants posit studies involving infants without

similar medical conditions are inapplicable.40 Further, Defendants note Mannen’s

studies involved tests using infants wearing only a diaper, not a full swaddle and

multiple layers of clothing as in the instant case.41

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 …”42 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.43 This contention is addressed in the Memorandum Opinion and Order

concerning Mannen’s expert testimony. For the reasons set forth in that decision,

the Court finds there is no merit to Defendants’ contention that Mannen’s studies,

and the subsequent opinions based on those studies, stand too far removed from the

facts present in this case to be admissible.

40
Id.
41
Id.
42
Gen. Motors Corp. v. Grenier, 981 A.2d 524, 529 (Del. Feb. 4, 2009) (internal
quotations omitted).
43
D.I. 168 at 20.
11
Mannen’s three studies sufficiently fit the facts of the case and constitute

sources reasonably relied on by an expert in pediatrics; accordingly, Hoffman’s

reliance on Mannen’s three studies will not preclude him from offering his opinion.

C. HOFFMAN’S OPINIONS FORMED USING DIFFERENTIAL DIAGNOSIS
METHODOLOGY ARE ADMISSIBLE.

In determining the cause of A.B.’s death, Hoffman utilized a differential

diagnosis technique, essentially ruling out all other possible causes of death until

concluding the inclined environment of the RnP caused A.B.’s death.44 Defendants

argue Hoffman utilized a flawed technique and take issue with Hoffman’s grouping

of potential diagnoses by systems.45 Defendants further posit Hoffman failed to

consider several alternative causes of death, and his failure to rule out those causes

renders his diagnosis inadmissible.46

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

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

history, reviews clinical tests, including laboratory tests, and excludes obvious (but

not all) alternative causes.”47 A doctor does not need to utilize all of those techniques

44
Dr. Hoffman’s Report at 16-18.
45
D.I. 168 at 26-27.
46
Id. at 29-32.
47
State v. McMullen, 900 A.2d 103, 117 (Del. Super. 2006).
12
to create a reliable differential diagnosis.48 “For instance, a physician may reach a

reliable differential diagnosis without himself performing a physical examination,

particularly if there are other examination results available.”49 This Court must

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

determine if his [ ] ultimate conclusions are reliable.”50 “So long as physicians

employ objective diagnostic techniques when performing a differential diagnosis,

their diagnosis will be reliable under Daubert ...”51 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.52

Defendants raise several issues with Hoffman’s methodology, but those relate

to the credibility of his opinion, not its admissibility. First, Defendants’ objection to

Hoffman’s use of systems to categorize different potential causes is easily dismissed.

Nothing about Hoffman’s organization of his report suggests that his methodology

differed in any material way from a differential diagnosis organized in another way.

48
Id.
49
Id. (internal quotations omitted) (quoting Kannakeril v. Terminix Intern., Inc., 128
F.3d 802, 807 (3d Cir. 1997)).
50
Id. (internal quotations omitted) (quoting Poust v. Huntleigh Healthcare, 998
F.Supp. 478, 496 (D.N.J. 1998)).
51
Id. at 117-18.
52
Id.
13
Defendants’ hyperfocus on the use of the word “systems” throughout Hoffman’s

report appears to misapprehend Hoffman’s approach.

Defendants argue Hoffman’s report does not adequately consider whether

A.B.’s medical conditions could have contributed to his alleged suffocation.

Hoffman opined A.B.’s medical conditions did not place him at an increased risk of

death, and that A.B. appeared to be at his “baseline state of health” the day of his

death.53 Hoffman’s supplemental report elaborates further on his opinion that A.B.’s

medical history did not contribute to the cause of death.54 Hoffman ultimately

determined A.B. rolled onto his side and died as a result.

Defendants next contend that Hoffman overlooked other plausible causes of

death. An expert does not, however, need to “rule out all possible causes of a

patient’s injury ...”55 Hoffman’s report explains that SIDS refers to any

unexplainable death of an infant.56 Hoffman notes that SIDS can be distinguished

from Accidental Suffocations or Strangulation in Bed (“ASSB”) when the infant dies

in a sleep environment where their nose and mouth were obstructed. 57 Plaintiffs

53
Dr. Hoffman’s Report at 6.
54
D.I. 209 Pls. Ex. K at 1-2.
55
McMullen, 900 A.2d at 116 n.63 (quoting Creanga v. Jardal, 886 A.2d 633, 639
(2005)).
56
Dr. Hoffman’s Report at 7.
57
Id.
14
allege such obstruction occurred in this case; thus, Hoffman’s report effectively rules

out SIDS as a possible cause of death. Defendants may attack the credibility of that

conclusion in cross-examination.

Further, while Hoffman’s initial report did not consider overheating as a

potential cause of death, Hoffman considered overheating as a potential factor in

A.B.’s death in his supplemental report. In that report, Hoffman explained the

temperature of the house coupled with the clothing A.B. wore led Hoffman to

determine no increased risk of overheating existed.58 Specifically, Hoffman noted

that parents are advised to dress their infants in one layer of clothing more than an

adult would be comfortable wearing to maintain a safe temperature.59 Hoffman’s

conclusion that A.B. was dressed appropriately may be contested during cross-

examination.

The guidance from previous cases considering the admissibility of a

differential diagnosis stresses the need for flexibility, and Daubert leans toward

admissibility if the information may assist the trier of fact. Accordingly, Hoffman’s

conclusion on A.B.’s specific cause of death, based on his examination of the facts

and his training and experience, is admissible.

58
D.I. 209 Pls.’ Ex. K.
59
Id. at 2-3.
15
D. HOFFMAN CANNOT RELY ON INCREASED RISK OF HARM TO ESTABLISH
CAUSATION.

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

statement that the RnP put A.B. “at increased risk for sleep related death.”60

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

causation in products liability cases.61 Defendants argue because Hoffman noted the

RnP’s design led to an increased risk, and subsequently based his opinion on that

notion, Hoffman’s opinion cannot be admitted as causation evidence.62

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

establish causation in products liability cases.63 At oral argument, Plaintiffs

acknowledged that increased risk standing alone does not equal causation under

60
D.I. 169 at 24 (quoting Dr. Hoffman’s Report at 18).
61
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).
62
D.I. 169 at 24.
63
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).
16
Pennsylvania law because the jury must later decide whether the increased risk was

a substantial factor in achieving causation.64 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.”65 Here, Hoffman offers a basis for specific causation which goes beyond

his reliance on increased risk. Moreover, Defendants have conceded that Plaintiffs

are not attempting to substitute increased risk for causation. Accordingly, Hoffman

may not testify that increased risk establishes causation.

IV. CONCLUSION

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

cause of death. Although Hoffman may not have fully addressed some of the

alternative explanations proposed by Defendants, those explanations may be

explored via cross-examination at trial. Daubert and the line of cases interpreting

its application in Delaware courts advise erring on the side of admitting expert

testimony if it will assist the trier of fact. Here, Hoffman unquestionably qualifies

64
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.
65
Tr., Oral Argument, C.A. No. N20C-01-067 PAW, at 147:7-15.
17
as an expert on infant safety conditions, including infant sleep conditions, and his

opinion reflects that expertise.

Hoffman does rely on Mannen’s reports and some biomechanical principles,

but Hoffman does not frame his testimony as that of a biomechanical expert and does

not attempt to provide expert testimony in the realm of biomechanics. For these

reasons, the Court shall admit Hoffman as an expert witness. He is prohibited,

however, from testifying that increased risk establishes causation.

IT IS SO ORDERED.

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

18