Dawn M. Clary v. Tristar Products, Inc.

[[COURTLISTENER_SUBOPINION {"id":"11198123","type":"100trialcourt","part":"other","author":null,"source_field":"html_with_citations"}]]
IN THE UNITED STATES DISTRICT COURT                       
                  FOR THE DISTRICT OF NEBRASKA                           

DAWN M. CLARY,                                                           

              Plaintiff,                     4:22CV3230                  

    vs.                                                                  
                                     MEMORANDUM AND ORDER                
TRISTAR PRODUCTS, INC.,                                                  

              Defendant.                                                 

    This matter is before the Court on Plaintiff’s Motion to Exclude Testimony of Robert 
Giachetti, Ph.D. (Filing No. 81).  For the reasons stated below, the motion will be granted in part. 
                     FACTUAL BACKGROUND                                  
    This action arises from an explosion and resulting injuries Ms. Clary incurred while using 
a  Power  Quick  Pot  model  Y6D-36  pressure  cooker  (the  “pressure  cooker”),  marketed  and 
distributed by Defendant Tristar Products, Inc. (“Tristar”).  (Filing No. 1; Filing No. 80-4 at 9.)   
    Dawn Clary alleges she used the pressure cooker to make a meal on July 17, 2020.  (Filing 
No. 1).  When the pressure cooker finished cooking, she released the pressure cooker’s steam valve 
and waited until the steam exited before opening the device.  (Filing No. 86-1 at 10.)  After steam 
had stopped exiting the valve, Ms. Clary allegedly grabbed the pressure cooker’s lid and rotated 
the lid to the open position.  (Filing No. 86-1 at 10.)  The lid then blew off, and the pressure 
cooker’s contents exploded onto her, burning her face, chest, and arms (the “explosion”).  (Filing 
No. 86-1 at 10-11.)  Ms. Clary has brought this action against Tristar for her injuries from the 
explosion, alleging defective design, negligence, breach of express warranty, breach of implied 
warranty of merchantability, and failure to warn. (Filing No. 1.)         
    The present motion seeks to exclude parts of the testimony of Dr. Robert Giachetti, 
Tristar’s expert witness.  (Filing No. 81.)  Ms. Clary moves to exclude Dr. Robert Giachetti’s 
“opinions as to the placement of Plaintiff’s arms at the time of the explosion.”  (Filing No. 81.)  
Specifically, Ms. Clary seeks to exclude Dr. Giachetti’s “opinion that Plaintiff’s arms were on the 
base of the machine[.]”  (Filing No. 81.)                                 
    Dr. Giachetti is a licensed professional engineer who holds a Ph.D., M.S. and B.S. in 
Mechanical Engineering.  (Filing No. 86-7.)  Dr. Giachetti “specializes in biomechanics, human 
performance,  machine  design,  and  dynamic  systems.”  (Filing  No.  86-7.)    His  educational 
background has “a heavy emphasis on dynamics,” the study of how things move and are moved.  
(Filing No. 86-8 at 12.)  He has “substantial education and teaching experience in areas related to 
human movement, human muscular control, postural dynamics, and solid and fluid dynamics.”  
(Filing No. 86-8 at 12.)  He has previously testified as an expert witness in “numerous cases 
regarding human movement and effort generation.”  (Filing No. 86-8 at 13.)  He has participated 
in “numerous joint examinations of pressure cookers” and performed independent research on the 
trajectory of expulsed contents from a pressurized pressure cooker and its potential for scald 
injuries, which was published in the Journal of Burns.  (Filing No. 86-8 at 13; Filing No. 84-4.) 
Per Dr. Giachetti, his “experience, training, education, publications and research” qualify him to 
render opinions regarding burn causation.  (Filing No. 86-8 at 3.)        
    Dr. Giachetti opines that Ms. Clary’s testimony and discovery responses are inconsistent 
with her burns and the testing of the pressure cooker.  (Filing No. 84-3 at 19.)  In her deposition, 
Ms. Clary testified that she had her hands on the pressure cooker’s lid right before its contents 
exploded onto her.  (Filing No. 86-1 at 10.)  According to Dr. Giachetti, however, Ms. Clary’s 
burns were consistent with her looking downwards with “her hands on the base” of the pressure 
cooker, not on the lid:                                                   
    Had her hands been on the lid performing an opening effort when the cover opened, 
    her forearms would have been in the direct path of the escaping contents, however, 
    she did not sustain severe burns to her forearms.  With an energetic dispersion as is 
    expected with a 3PSI release, the contents ejected from the pressure cooker without 
    flowing over the side, avoiding her hands and forearms.              
    (Filing No. 84-3 at 19.)                                             
    Dr. Giachetti asserts his analysis and conclusion rely on “two simple scientific facts:” (1) 
burns occur where “hot fluid touches the skin,” and (2) fluid exits a pressure cooker “without 
passing through the walls or lid of the pressure cooker[.]”  (Filing No. 86-8 at 5.)  Relying on his 
published study, which tracked the trajectory of water emitting from a pressurized pressure cooker 
onto a 50th percentile female mannequin, Dr. Giachetti concluded Ms. Clary’s hands and arms 
would have been “in the direct path of the broadly escaping contents and should be severely 
scalded” if she had her hands placed on the lid at the time of the explosion.  (Filing No. 86-8 at 6-
8).                                                                       
    To determine whether Ms. Clary had been severely scalded in the explosion, Dr. Giachetti 
“relied upon the  medical records to  ascertain the  locations of  burns diagnosed by medical 
professionals.”  (Filing No. 86-8 at 2.)  Dr. Giachetti declared, “My experience, training, education, 
publications and research qualifies me to render opinions regarding burn causation . . . I do not 
diagnose injury.”  (Filing No. 86-8 at 3.)  Dr. Giachetti does not perform “burn pattern” analysis, 
which analyzes the type of contact that caused scalding.  (Filing No. 86-8 at 3.)  His analysis 
instead “examines the bulk overall placement of burns.”  (Filing No. 86-8 at 3.)   
    Ms. Clary’s medical records indicate Ms. Clary had partial-thickness burns to her face on 
her nose and chin and on her chest and upper breasts.  (Filing No. 88 at 15.)  She had superficial 
burns to the “forehead and bilateral antecubital spaces.”  (Filing No. 88 at 15.)  The records also 
contain a diagram which indicates that Ms. Clary had burns on chest and breast area and both inner 
elbows.  (Filing No. 88 at 9.)  In addition, Ms. Clary’s medical records also include a statement 
that reads:                                                               
    Sometime shortly prior to arrival she was using a food steamer and says that though it got 
    stuck.  She was holding the steamer while her boyfriend was trying to get a little off.  The 
    lid popped often the hot liquid splashed onto her face and upper chest. 
    (Filing No. 88 at 4.)                                                
    Based on his analysis and the materials provided to him, Dr, Giachetti opined at his 
deposition that Ms. Clary “should have substantial burns on both forearms, which are not recorded 
in the medical records” if Ms. Clary had her hands on the lid as she claims.  (Filing No. 84-1 at 
155).  “[B]oth of her forearms should just be as scalded as everywhere else where she had received 
burns, if not more so.  [Her arms] would have been very close to where the water came out, and at 
a high temperature.”  (Filing No. 84-1 at 154-55.)  At his deposition, Dr. Giachetti was presented 
with a photograph of Ms. Clary’s injuries that show redness on her forearms, particularly her left 
forearm.  (Filing No. 84-1 at 165-166; Filing No. 84-2).  Dr. Giachetti stated he saw “redness 
there[,]” but the medical personnel only identified burns near Ms. Clary’s elbows.  (Filing No. 84-
1 at 166.)                                                                
                      STANDARD OF REVIEW                                 

    Federal Rule of Evidence 702 and Daubert govern the admissibility of expert testimony 
and give the Court a gatekeeping responsibility to ensure that all expert evidence is relevant and 
reliable.  Kumho Tire Co. v. Carmichael,
526 U.S. 137, 147
(1999); Daubert v. Merrell Dow 
Pharmaceuticals, Inc.,
509 U.S. 579, 589
(1993); Sprafka v. Med. Device Bus. Servs., Inc.,
139 
F.4th 656, 660-61
(8th Cir. 2025).  Rule 702 was amended in 2023 “‘to clarify and emphasize that 
expert testimony may not be admitted unless the proponent demonstrates to the court that it is more 
likely than not that the proffered testimony meets the admissibility requirements set forth in the 
rule.’”  Sprafka,
139 F.4th at 660
(quoting Fed. R. Evid. 702, Advisory Committee’s Note to 2023 
Amendment).  After that amendment, “courts continue to have a gatekeeping role to assure that 
evidence admitted in a case is both relevant and reliable.”
Id.
(quoting Academy Bank, N.A. v. 
AmGuard Ins. Co.,
116 F.4th 768, 790
(8th Cir. 2024)).                    
    “As the gatekeeper, the district court’s role is to discern expert opinion evidence based on 
‘good grounds’ from subjective speculation that masquerades as scientific knowledge.”
Id.
(quoting Ackerman v. U-Park, Inc.,
951 F.3d 929, 933
(8th Cir. 2020)).  Rule 702 requires the 
proponent of expert testimony to demonstrate to the court that “it is more likely than not” that (1) 
the expert’s knowledge will “help the trier of fact to understand the evidence or to determine a fact 
in issue;” (2) “the testimony is based on sufficient facts or data;” (3) “the testimony is the product 
of reliable principles and methods;” and (4) “the expert’s opinion reflects a reliable application of 
the principles and methods to the facts of the case.”  Fed. R. Evid. 702. 
    Reliability of an expert opinion involves consideration of “(1) whether the scientific 
technique can be or has been tested; (2) whether the theory or technique has been subjected to peer 
review and/or publication; (3) the known rate of error for the technique or theory and the applicable 
standards for operation; and (4) whether the technique is generally accepted.”  Academy Bank, 
N.A. v. AmGuard Ins. Co.,
116 F.4th 768, 790
(8th Cir. 2024); In re Bair Hugger Forced Air 
Warming Devices Prod. Liab. Litig.,
9 F.4th 768
, 777 (8th Cir. 2021).     
    Other considerations recognized since Daubert include “whether the experts are proposing 
to testify about matters growing naturally and directly out of research they have conducted 
independent of the litigation, or whether they have developed their opinions expressly for purposes 
of testifying.”
Id.
(quotation omitted).  These factors are not “exhaustive or limiting.”  Presley v. 
Lakewood Eng’g & Mfg. Co.,
553 F.3d 638, 643
(8th Cir. 2009).  Nor do courts need to consider 
each factor in each case; factors should only be relied upon to the extent that they are relevant. 
Shuck v. CNH Am., LLC,
498 F.3d 868, 874
(8th Cir. 2007).  Ultimately, courts must evaluate the 
reliability of expert testimony based on the facts of the case before them.  Presley,
553 F.3d at 643
.  
The Court has “‘considerable leeway’” in determining whether “‘particular expert testimony is 
reliable.’”  Academy Bank, N.A.,
116 F.4th at 791
.                        
    A district court must continue to perform its gatekeeping role even after “initial expert 
qualifications and usefulness to the jury are established, however[.]”  Wheeling Pittsburgh Steel 
Corp. v. Beelman River Terminals, Inc.,
254 F.3d 706, 715
(8th Cir. 2001).  The expert’s actual 
testimony cannot exceed the scope of the expert’s expertise, which would “render expert testimony 
unreliable under Rule 702, Kumho Tire, and related precedents.”
Id.
Expert opinions “must stay 
within the bounds of what can be concluded from a reliable application of the expert’s basis and 
methodology.”  Fed. R. Evid. 702, Advisory Committee’s Note to 2023 Amendment.  Experts 
should not make unsupported assertions admittedly beyond their area of expertise.  See Anderson 
v. Raymond Corp.,
340 F.3d 520, 524
(8th Cir. 2003) (upholding district court’s decision to 
exclude testimony where an engineering expert was to testify to stand-up lift trucks and he 
admitted he was not an expert in stand-up lift trucks nor had professional experience with them) 
(cited by Grummer v. Budget Truck Rental, LLC, 5:220-CV-5177,
2024 WL 926963
, at *5 (W.D. 
Ark. Mar. 4, 2024)).                                                      
                          DISCUSSION                                     
    Ms. Clary moves to exclude Dr. Giachetti’s opinion on Ms. Clary’s hand placement, 
arguing his opinion is unreliable and based on “unsound methodology.”  (Filing No. 82 at 1.)  Ms. 
Clary asserts that Dr. Giachetti’s expertise as a biomechanical engineer and his methodology do 
not enable him to render a reliable opinion on burn injuries or a derivative opinion on the placement 
of Ms. Clary’s hands based on her burn injuries.  (Filing No. 82.)  The issue before the Court is 
not whether Dr. Giachetti is qualified to testify as an expert generally, but whether his proffered 
opinion on Ms. Clary’s hand placement is within his expertise.            
    Ms. Clary primarily relies on a prior case in which Dr. Giachetti’s expert testimony was 
excluded because of unreliable methodology.  In Williams v. Tristar Prods., Inc., another case 
arising from a pressure cooker explosion, the court excluded Dr. Giachetti’s proffered opinion on 
the plaintiff’s arm placement at the time of the explosion.
418 F. Supp. 3d 1212
(M.D. Ga. Aug. 
27, 2019).  There, the plaintiff did not challenge Dr. Giachetti’s engineering qualifications.  Id. at 
1223.  The plaintiff contended Dr. Giachetti’s opinions were irrelevant and unreliable because Dr. 
Giachetti relied on an examination of photographs of the plaintiff’s burn injuries to theorize how 
“scalding liquid came to be on [the p]laintiff’s skin and whether those burn patterns would be 
consistent with her testimony.”  Id. at 1224.                             
    The plaintiff in Williams argued Dr. Giachetti had inconsistent evidence to establish that 
the burns were more consistent with her forcing the lid of the pressure cooker open and spilling 
the contents on herself than an explosion of hot contents onto her skin.  Id.  Dr. Giachetti stated a 
lack of burns on the plaintiff’s right elbow supported his hypothesis that she had tried to force open 
the subject cooker.  Id.  However, the plaintiff did have burns on her right elbow.  Id.  Dr. Giachetti 
also admitted he did not consider what clothing the plaintiff was wearing at the time of the incident 
and contended it was irrelevant.  Id.   The court noted, “Some clothing is more protective than 
others[,]” and expressed concerns that burn patterns would be different depending on the clothing 
worn.  Id.  Finally, Dr. Giachetti’s opinion that the pressure cooker was forcibly opened directly 
conflicted with the plaintiff’s “consistent and repeated testimony” that she did not forcibly open 
the pressure cooker.  See id.                                             
    The court in Williams deemed Dr. Giachetti’s opinion “mere speculation” and found that 
his  analysis  of  her  burn  injuries  were  not  “sufficiently  based  on  scientific  fact  or  reliable 
methodology and should be excluded from trial.”  Id.  With the plaintiff’s consent, the court 
allowed Dr. Giachetti to testify to his theory as to how the incident occurred but excluded “any 
opinions based on his evaluation of Plaintiff's burn injuries.”  Id.      
    Ms. Clary argues that the facts in this case are sufficiently similar for this Court to exclude 
Dr. Giachetti’s opinion on Ms. Clary’s hand placement.  (Filing No. 82 at 3-4.)  First, Ms. Clary 
contends  Dr.  Giachetti  relied  on  inconsistent  evidence  to  develop  his  opinion  because  the 
photograph of Ms. Clary’s injuries “clearly demonstrates” Ms. Clary had burns on her forearms.  
(Filing No. 82 at 4.)  Second, Ms. Clary contends Dr. Giachetti failed to adequately consider or 
test the effect of Ms. Clary’s clothing at the time of the incident on the severity of her burns.  
(Filing No. 82 at 4.)  Finally, Ms. Clary contends that the study Dr. Giachetti conducted did not 
account for the trajectory of the lid and the pressure cooker’s contents when the user had her hands 
on the lid, like Ms. Clary has repeatedly testified.  (Filing No. 82 at 5.) 
    Tristar argues that the court’s reasoning in Williams does not apply to Dr. Giachetti’s 
testimony here.  First, Tristar contends that Dr. Giachetti relied on the medical records, which did 
not diagnose burns to her forearms or hands.  (Filing No. 85 at 14.)  Further, Tristar contends the 
burns that are apparent from the photographs are not “severe,” and Dr. Giachetti’s opinion is based 
on a lack of severe burns to Ms. Clary’s forearms and hands.  (Filing No. 85 at 3, 5-6.)  Second, 
Tristar argues that Ms. Clary’s clothing at the time of the incident is irrelevant.  (Filing No. 85 at 
15.)  Dr. Giachetti stated that Ms. Clary suffered burns to clothed and unclothed areas, which 
indicated that her shirt was “not protective.”  (Filing No. 86-8 at 4.)  Therefore, whether the shirt 
was long-sleeved or short-sleeved would not have affected whether she would have been severely 
burned if “her hands and forearms were in the direct path of the broadly ejecting contents.”  (Filing 
No. 86-8 at 4.)  Finally, Tristar asserts that Dr. Giachetti relied on the medical records in forming 
his theory on hand placement, and the medical record indicates Ms. Clary said her boyfriend 
opened the pressure cooker while she held the pressure cooker down.  (Filing No. 85 at 14.)  This 
purported  statement, along  with  the  medical  records,  photographs,  product  testing,  and  Dr. 
Giachetti’s article, provided sufficient facts for Dr. Giachetti to form an opinion on Ms. Clary’s 
hand placement.  (Filing No. 85 at 14.)                                   
    Additionally, Tristar distinguishes Williams insofar as Dr. Giachetti has published new 
research that supports his theory on content dispersal and hand placement.  (Filing No. 85 at 18-
19.)  At the time Williams was published in 2019, Dr. Giachetti’s article in Journal of Burns had 
not yet been published.  (Filing No. 84-4).  This article is peer-reviewed and provides direct support 
for his theory that Ms. Clary’s arms would have been in the direct path of the pressure cooker’s 
exploding contents if her hands were on the lid.  (Filing No. 84-4).  Tristar cites a later court 
opinion from the same district, Copeland v. Tristar Prods., Inc., 5:22-CV-00212 (CAR), which 
admitted similar expert testimony by Dr. Giachetti after publication of his article. (Filing No. 85 
at 18; Filing No. 86-9.)  Specifically, the Court allowed Dr. Giachetti to testify that the contents 
from a pressure cooker would have shot out horizontally and radially, which was consistent with 
Dr. Giachetti’s opinion on the decedent-user’s hand placement.  (Filing No. 85 at 18-19; Filing 
No. 86-9.)                                                                
    The Court agrees that Dr. Giachetti is qualified to testify as to the trajectory of the pressure 
cooker’s expulsed contents based on burn placement.  His analysis based on burn placement is 
based on sufficiently reliable methodology.  As Dr. Giachetti outlined, his analysis was premised 
on two scientific facts (1) hot fluids burn skin, and (2) fluids cannot permeate the solid walls of a 
pressure cooker.  Based on his scientific study, which was peer-reviewed, Dr. Giachetti determined 
the trajectory of the expulsed fluids would have contacted Ms. Clary’s hands had they been on the 
lid at the time of the explosion.  Because Ms. Clary’s shirt was not protective of other areas of 
skin, whether the shirt was long-sleeved or short-sleeved was irrelevant to Dr. Giachetti’s analysis.   
    Dr. Giachetti has premised his opinion on the placement of Ms. Clary’s hands during the 
incident on the location of “severe burns” on her body.  Unlike in Williams, Dr. Giachetti has not 
ignored an established fact as to the placement of Ms. Clary’s severe burns.  Here, the University 
of Nebraska Medical Center did not diagnose burns to Ms. Clary’s forearms or hands, and the 
medical records did not indicate any burns to her forearms or hands.  Therefore, he did not rely on 
inconsistent or incorrect evidence to form his opinion as he had in Williams.   
    As a result, the Court finds that Defendant has shown that it is more likely than not that Dr. 
Giachetti expert knowledge will help the jury understand the evidence and help them determine 
how this accident happened.  Dr. Giachetti’s opinions are based on sufficient facts and data, are 
the product of reliable principals and methods, and reflect a reliable application of the principles 
and methods to the facts of the case.  Therefore, Dr. Giachetti may testify as to Ms. Clary’s hand 
placement based on the trajectory of the pressure cooker’s expulsed contents and the location of 
Ms. Clary’s burns.                                                        
    However, the Court is concerned about any potential testimony that would have Dr. 
Giachetti diagnose the degree of burns to Ms. Clary’s forearms.   Tristar contends that the 
photograph of Ms. Clary’s burns indicates that the potential burns on her arms are not “severe,” 
and Dr. Giachetti “explained the minor burns to her left forearm (redness) should be as severe as 
her other burns if she opened the unit.”  (Filing No. 85 at 15, 14.)  As Ms. Clary aptly highlighted, 
Dr. Giachetti is not a medical professional, and his 2020 testing did not establish the severity of 
burns that would occur in a pressurized explosion.  (Filing No. 94 at 4-6; Filing No. 84-4.)  This 
Court is not satisfied that Dr. Giachetti’s expertise in biomechanical engineering enables him to 
make any burn diagnoses additional to those made by the medical professionals at University of 
Nebraska Medical Center, even if to diagnose the burns to Ms. Clary’s forearms as minor.  Dr. 
Giachetti’s  background  and  experience  does  not  indicate  that  he  has  the  qualifications  or 
experience to diagnose burns.  Indeed, Dr. Giachetti agrees that he is not qualified to make medical 
diagnoses or conduct “burn pattern” analysis.  (See Filing No. 86-8 at 3.)  Therefore, this Court 
will exclude any testimony as to Dr. Giachetti’s diagnosis of Ms. Clary’s injuries or any opinion 
based on Dr. Giachetti’s diagnosis of Ms. Clary’s injuries. 
      Accordingly, 
      IT IS ORDERED: 

   1.  Plaintiff's Motion to Exclude Testimony of Robert Giachetti, Ph.D.  (Filing No.  81) is 
      granted in part and denied in part. 
   2.  Defendant may  not present  any  expert testimony  from Dr.  Giachetti  on  any  medical 
      diagnosis  not made by medical professionals  or any testimony  derived from his  own 
      diagnosis of Ms. Clary’s burns. 
   3.  Dr. Giachetti may testify to his opinion on Ms. Clary’s hand placement at the time of the 
      explosion based on the location of her burns identified in her medical records. 

      Dated this 5th day of November, 2025. 
                                          BY THE COURT:          □        □ 
                                         Drsam/)    Pages 
                                          United States District Judge