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 Expert Testimony
regarding Rebreathing to D.R.E. 702;

DENIED, in part and GRANTED, in part.

Robert Leoni, Esq., of 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 Michael Leshner, a

professional engineer who intends to testify about the risk of rebreathing caused by

the design of the RnP.2 Defendants also move to exclude rebreathing testimony of

Plaintiffs’ other experts because those experts rely on Leshner’s report.3 Only the

admissibility of Leshner’s testimony, and any additional rebreathing testimony, will

be examined below.

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:

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 Test. Regarding Rebreathing, D.I. 164.
3
Id. Separately, Defendants have moved to exclude the testimony of all of those
additional experts, with the exception of Myers, which the Court addresses in its
separate Memorandum and Orders. Defs.’ Mot. to Exclude Pls.’ Expert Darlene
Vasbinder-Calhoun, D.O., D.I. 179; Defs.’ Mot. to Exclude Pls.’ Expert Benjamin
Hoffman, M.D., D.I. 168; Defs.’ Mot. to Exclude Pls.’ Expert Erin Mannen, PH.D.,
D.I. 184; Defs.’ Mot. to Exclude Pls.’ Expert Dennis Rosen, M.D., D.I. 177; Defs.’
Mot. to Exclude Pls.’ Expert Wayne Ross, M.D., D.I. 174.
2
(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.4

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. 702.5 “Once

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

testimony is both relevant and reliable.”6 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

applied to the facts in issue.”7 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

4
D.R.E. 702.
5
Bowen v. E.I. DuPont de Nemours & Co., Inc., 906 A.2d 787, 795 (Del. 2006).
6
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)).
7
Gen. Motors Corp. v. Grenier, 981 A.2d 531, 536 (Del. 2009) (internal quotations
omitted) (quoting Daubert, 509 U.S. 579, at 592-93).
3
(5) the expert testimony will not create unfair prejudice or
confuse or mislead the jury.8

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

science and derived from the scientific method. 9 Expert testimony is relevant when

it assists the trier of fact to understand the evidence or to determine 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.10 This

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

factors are reasonable measures of reliability in a particular case.”11 “A strong

preference exists for admitting evidence that may assist the trier of fact.”12

III. ANALYSIS

Defendants do not challenge Leshner’s credentials as an expert, only the

methodology he employed, the reliability of his findings, and the relevance of his

opinion to the instant case.13 As Plaintiffs’ other experts cite to Leshner, indicating

8
Norman v. All About Women, P.A., 193 A.3d 726, 729-30 (quoting Smith v. Grief,
2015 WL 128004 (Del. Jan. 8, 2015)).
9
Daubert, 509 U.S. at 590-94.
10
Bowen, 906 A.2d at 794 (citing Daubert, 509 U.S. at 595).
11
Grenier, 981 A.2d at 536 (internal quotations omitted) (quoting Kumho Tire Co.,
Ltd. v. Carmichael, 526 U.S. 137, 141 (1999)).
12
Norman, 193 A.3d at 730.
13
D.I. 164 at 2.
4
some level of reliance on his report, the Court first considers the admissibility of

Leshner’s report.

Leshner formulated his report by conducting a test using a doll placed in

several different infant sleep products.14 Using a model lung placed within the doll,

Leshner measured the levels of carbon dioxide over time after placing the doll in

various positions within the sleep products.15 While performing the test using a

version of the RnP, Leshner tested three different layers of “soft material.”16 Leshner

ran each test three times.17

Leshner states five conclusions in his report:

(1) An infant sleeping prone on a standard crib mattress and cotton
sheet does not experience a hazardous level of carbon dioxide
rebreathing; (2) an infant sleeping prone on a soft sleep surface
may experience elevated levels of carbon dioxide rebreathing; (3)
when sleeping prone on a flat sleep surface, turning the infant’s
head is an effective countermeasure to rebreathing; (4) when prone
or side-facing in the Rock ’n Play, an infant is in a very hazardous
position due to the risk of elevated levels of carbon dioxide
rebreathing; (5) the design of the Rock n’ Play is defective and
unreasonably dangerous to infants due to the risk of hazardous
carbon dioxide rebreathing.18

14
Ex. C to Pls.’ Answering Br., D.I. 213, at 5 (“Leshner’s Report”).
15
Id. at 6.
16
Id. at 12.
17
Id. at 5.
18
Id. at 13-14.
5
Of his conclusions, the first three provide points of comparison for the final

two. Taken together, Leshner posits the RnP’s design is defective because an infant

laying side-facing in the RnP faces a heightened risk of “hazardous” levels of carbon

dioxide.19 As his first three opinions serve to contextualize the final two, the Court’s

analysis must focus on the admissibility of Leshner’s final two conclusions.

A. LESHNER DID NOT UTILIZE A SUFFICIENTLY RELIABLE
METHODOLOGY TO EXAMINE THE SPECIFIC INCREASE IN CARBON
DIOXIDE AN INFANT WOULD BE EXPOSED TO IN THE RNP, MAKING HIS
TESTIMONY INADMISSIBLE.

“Reliable means testimony must be supported by appropriate validation—i.e.,

good grounds, based on what is known.”20 Two of the factors Daubert instructs this

Court to consider are “whether the expert’s theory has or can be tested,” and “the

known or potential error rate associated with the theory.”21 Defendants devote much

of their opening brief to a discussion of Rovid v. Graco Children’s Products Inc.,22 a

federal case in which the court excluded a similar report prepared by Leshner. The

Rovid court took issue with Leshner’s failure to perform more than a single test, the

lack of statistical rigor applied to his test results, and Leshner’s failure “to explain

19
Id.
20
Tumlinson v. Advanced Micro Devices, Inc., 2013 WL 7084888 at *2 (Del. Super.
Oct. 15, 2013), aff’d, 81 A.3d 1264 (Del. 2013) (internal quotations omitted)
(quoting Daubert, 509 U.S. at 597).
21
Id.
22
2018 WL 5906075, at *4 (N.D. Cal. Nov. 9, 2018).
6
or show whether he controlled for the position of the doll on the mattress.”23 Further,

the court found Leshner’s conclusions were unsupported by his data.24 Defendants

also point to Leshner’s decision to use slightly different locations in each retest, “a

couple inches apart,”25 as a fatal flaw in Leshner’s methodology rendering his results

impossible to reproduce because Leshner failed to document the different locations

the measurements derived from.26

Unlike Rovid, Leshner repeated his testing three times.27 In addition, Leshner

documented an approximation of the locations he used when retesting each sleep

setting through photographs of each location.28 These photographs provide an

opportunity for a subsequent expert to recreate Leshner’s procedure. As a result,

Leshner’s theory may be retested and satisfies one factor for reliability under

Daubert.

However, Leshner is unable to quantify the statistical reliability of his

numbers. A review of the data collected by Leshner shows a significant variation in

23
Id.
24
Id. at *5.
25
Ex. L to Pls.’ Answering Br., D.I. 213, at 35 (“Leshner’s Deposition”).
26
D.I. 164 at 24.
27
Leshner’s Report at 5; see also App. F to Leshner’s Report.
28
Leshner’s Report at 8-11.
7
the carbon dioxide readings throughout Leshner’s retests.29 In his deposition,

Leshner explained that he could not quantify what statistical deviation between his

measurements would “give him pause.”30 Regarding the test of a side-facing doll in

an RnP, a test of particular consequence to the instant case given the facts, Leshner

opined “[i]t’s measuring three different locations, three different configurations. So

that spread between 10 and 17 does not give me any pause.” 31 Yet, he does not

provide any further explanation as to why that would be true or offer any citation to

reaffirm that stance.

Leshner states the variation in the position of the doll when retesting by one

or two inches would not affect the reliability of the data.32 However, the fluctuations

between the results demonstrate that the one- or two-inch variation in position may

have affected the recorded level of carbon dioxide. Leshner provides no other

explanation or additional variables, in his report or in his deposition, that would

account for this fluctuation in results. Accordingly, the Court cannot have

confidence that Leshner’s testing utilized a reliable methodology under Daubert,

and, thus, this Court cannot admit Leshner’s expert testimony.

29
App. F to Leshner’s Report.
30
Leshner’s Deposition at 135-37.
31
Id.
32
Leshner’s Deposition at 121.
8
B. LESHNER’S CONCLUSIONS ARE NOT ADEQUATELY SUPPORTED BY HIS
DATA.

Even if the Court accepted Leshner’s methodology as reliable, his conclusions

are not properly grounded in the data he presents. Though the focus under Daubert

is on principles and methodology and not on conclusions, other factors that might be

considered include whether an expert has unjustifiably extrapolated from an

accepted premise to an unsupported conclusion.33 In addition, a court may exclude

expert testimony on the ground that an expert’s purported methodology fails to

explain his final conclusions.34

Leshner opines that the elevated level of carbon dioxide an infant may be

exposed to as a result of the RnP’s design are “very hazardous” and “unreasonably

dangerous.”35 This contrasts to the carbon dioxide level found when testing a doll

placed on a “standard crib mattress,” which Leshner opines is not hazardous.36

As an initial matter, Plaintiffs conceded that Leshner’s testimony is limited to

showing the subject mattress performance in the tests relative to the other mattresses’

performance.37 Leshner expressly limited his task to that purpose: “I tested the CO2

33
General Elec. Co. v. Joiner, 522 U.S. 136, 146 (1997).
34
Id.
35
Leshner’s Report at 14.
36
Id. at 13.
37
Pls’ Answering Br., D.I. 213, at 10.
9
rebreathing. I tested it on hard surfaces and on soft surfaces. The softness correlates

with the CO2 rebreathing.”38 Thus, even if Leshner’s testing involved a reliable

methodology, his conclusions based upon that testing should be limited to that

narrow scope and comparative nature. At best, only Leshner’s first, second, and

third conclusions reflect the limited nature of Leshner’s testing.

Further, Leshner’s results do not support his conclusions because his

rebreathing results have no objective benchmark or threshold to be compared

against. When asked to provide a threshold of what level of carbon dioxide poses a

risk, Leshner declined to do so.39 Without providing an objective way to quantify

hazardous levels of carbon dioxide, Leshner’s conclusions as to which sleep surfaces

are safe, and which are not, appears to reduce to Leshner drawing an arbitrary line.

Leshner’s definition of “hazardous” does not help. Leshner stated at his

deposition: “…when you test [a mattress] compared to a bunch of other things, some

things are two, three, four, five times higher. The stuff on the low end is the least

hazardous… [O]nce you get to three, four times the normal level, certainly that

would be hazardous.”40 Without supporting evidence or qualifying expertise,

Leshner cannot merely assert that any amount of CO2 rebreathing is hazardous.

38
Leshner’s Deposition at 98.
39
Leshner’s Deposition at 37-40.
40
Leshner’s Deposition at 184.
10
Further, Leshner’s proposed definition renders his “hazard”-related conclusions

misleading and meaningless. The Court finds Leshner’s testing and results fail to

explain his final conclusions, which provides an independent basis—distinct from

the above discussed unreliable methodology—for excluding Leshner’s testimony.

C. THE OTHER EXPERTS MAY NOT RELY UPON LESHNER’S REPORT OR
DATA AND MAY ONLY OPINE ON REBREATHING IF INDEPENDENTLY
PERMITTED TO DO SO BASED ON THEIR EXPERTISE.

Though the Court will not permit Leshner to testify as an expert witness, the

Court must still consider whether Plaintiffs’ other experts may testify regarding

rebreathing. 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 …” Leshner’s

conclusions, for the reasons stated above, do not meet that requirement, and cannot

be relied upon by any of Plaintiffs’ experts.

Given the aforementioned flaws in Leshner’s methodology, the data presented

by Leshner may be not utilized by the other experts. More, the other experts’

testimony may not delve into what level of carbon dioxide the infant would be

exposed to, or how great a discrepancy in the carbon dioxide levels between the two

surfaces would be, if those conclusions are based exclusively on Leshner’s report.

However, the other experts may conclude there is a differing exposure to carbon

11
dioxide levels across different infant sleeping products if such a conclusion is

properly supported by their own expertise or other peer-reviewed studies.41

Mannen’s overall conclusions on rebreathing are addressed in the Daubert

motion surrounding the admissibility of her entire report, but one note bears

repeating here. Mannen’s opinion on rebreathing relies, in part, on a statistical

analysis of Leshner’s data.42 After that analysis, Mannen opined “that in a side-lying

or a 90-degree head turn situation, that an infant would experience significantly

increased CO2 inhalation simply due to the design of the product.”43 As Mannen’s

final conclusion regarding the level of CO2 an infant would experience in the RnP

was calculated with the data from Leshner’s unreliable methodology, that conclusion

must be struck from her testimony.

However, Mannen’s testimony regarding rebreathing that does not rely on

Leshner’s methodology is admissible. Mannen’s other conclusions regarding

whether an infant would be at risk for rebreathing in the RnP were based on her

examination of an RnP, her peer-reviewed research, and her expertise as a

biomechanical engineer.44 Accordingly, Mannen may still opine: “with this extreme

41
Leshner’s Report at 5-6; see also App. C to Leshner’s Report.
Ex. M to Defs.’ Mot. to Exclude Test. Regarding Rebreathing, D.I. 164, at 28 (“Dr.
42

Mannen’s Report”).
43
Id. (emphasis added).
44
Dr. Mannen’s Report at 3-4.
12
curvature [of the plastic support piece in the RnP], a normal head rotation of 90

degrees will result in contact of the baby’s face with the soft plush surface. This

constitutes a dangerous rebreathing situation as the infant’s face can be directly in

contact with plush soft goods, not a mesh material or a surface with free airflow.”45

Calhoun’s opinions regarding rebreathing appear to be reliant on Leshner’s

report.46 She directly cites to Leshner’s conclusions regarding hazardous design of

the RnP.47 She cites to Leshner’s Report for the proposition that rebreathing occurs

when a side-facing infant comes into contact with the side of the RnP.48 Plaintiffs

contend Calhoun relies on studies independent of Leshner to support her rebreathing

opinions, but the extent of that independent reliance appears to reduce down to

Calhoun concluding that rebreathing can occur when an infant’s face comes into

contact with a soft fabric. Most of Calhoun’s discussion of rebreathing refers to

either Leshner’s report directly, or Mannen’s interpretation of that report. Calhoun

also does not appear to add any of her own specialized knowledge or training to the

discussion of rebreathing. Thus, Calhoun’s testimony regarding rebreathing must be

excluded.

45
Dr. Mannen’s Report at 28.
Ex. E to Defs.’ Mot. to Exclude Test. Regarding Rebreathing, D.I. 164, at 17 (“Dr.
46

Calhoun’s Report).
47
Id.
48
Id.
13
Hoffman reviewed Leshner’s Report49 but, as a pediatrician, possesses an

independent basis to conclude rebreathing could have contributed to A.B.’s death.

To the extent that he seeks to discuss Leshner’s Report, that testimony must be

excluded. Hoffman’s conclusion that “any attempts to breathe would have been

hindered by CO2 rebreathing” is admissible to help explain Hoffman’s conclusion

that A.B. died of suffocation.50

Similarly, Rosen references Leshner’s Report but, as a pediatric

pulmonologist, possesses an independent basis to conclude rebreathing could have

played a part in A.B.’s death.51 Rosen may not refer to Leshner’s Report in his

testimony. Rosen may opine on the risk of rebreathing generally, and its potential

contribution to an infant suffocating.

Ross’s rebreathing testimony also does not rely on Leshner’s Report.52 Ross

addresses rebreathing only in the context of determining that “[e]ven if there was not

100% occlusion and A.B. was able to intake some small quantity of air, he would be

getting an insufficient amount of oxygen, and he would have been rebreathing

Ex. P to Defs.’ Mot. to Exclude Test. Regarding Rebreathing, D.I. 164, at 13 (“Dr.
49

Hoffman’s Report”).
50
Id. at 19.
51
Ex. Q to Defs.’ Mot. to Exclude Test. Regarding Rebreathing, D.I. 164, at 19-20
(“Dr. Rosen’s Report”).
Ex. R to Defs.’ Mot. to Exclude Test. Regarding Rebreathing, D.I. 164, at 5-6 (“Dr.
52

Ross’s Report”).
14
dangerous levels of carbon dioxide.”53 As a forensic pathologist, Ross possess an

independent basis to conclude that rebreathing may have factored into A.B.’s death.

Ross may not refer to Leshner’s Report in his testimony; however, Ross may opine

on the risk of rebreathing generally, and its potential contribution to an infant

suffocating.

Lastly, Myers’s report references Leshner’s Report in the context of

suggesting that, had Defendants tested the RnP for a risk of rebreathing, their results

would have mirrored Leshner’s.54 That testimony must be excluded, because it

presupposes that Leshner’s conclusions are admissible. Myers may testify why he

considers the testing Defendants conducted regarding rebreathing to be insufficient,

absent any reference to the results of Leshner’s Report, and he may testify as to how

the design facilitates rebreathing by allowing an infant to press his face against the

soft fabric.

IV. CONCLUSION

Leshner did not utilize a reliable methodology, and his conclusions are

unsupported by his data. Accordingly, his expert report, and any testimony from

other experts relying on Leshner’s Report, must be excluded. The other experts may

53
Id. at 5.
54
Ex. S to Defs.’ Mot. to Exclude Test. Regarding Rebreathing, D.I. 164, at 45
(“Myers’s Report”).
15
testify regarding rebreathing only to the extent that they rely on other peer-reviewed

studies or their own expertise. That testimony may not touch on Leshner’s Report

or any conclusions reliant on his methodology.

IT IS SO ORDERED.

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

16