Evidentiary Standard of Reliability is lower than the merits standard of correctness

Evidentiary Standard of Reliability is lower than the merits standard of correctness;Court admits the testimony of Human Factors Expert Witness regarding the adequacy of the product’s warning labels in this failure-to-warn suit

In a products liability action, Plaintiffs Timothy and Jean Moore filed a failure-to-warn lawsuit against Defendant Combe Inc., the manufacturer of the Just For Men brand of hair dye products. The Moores alleged that Combe knew or should have known that their products could cause vitiligo and/or skin depigmentation but failed to adequately warn users about this risk. They specifically pointed out that Just For Men Control GX Grey Reducing Shampoo (“Control GX”) contains a chemical known as p-Phenylenediamine (“PPD”), which can pose health risks when it comes into contact with the skin, one of these risks being vitiligo. 

Timothy Moore had been using Control GX since 2017, and in the subsequent years, he developed vitiligo. He claimed that he only became aware of the connection between PPD and vitiligo in 2020 and argued that Combe’s product packaging, inserts, and marketing materials did not adequately convey the risk associated with their products. 

During the discovery process, the Moores presented Lila Fitzgerald Laux, Ph.D., as an expert witness in the field of human factors engineering. In her report, Laux asserted that Just For Men products failed to provide sufficient warning about the risk of vitiligo. She explained that an effective safety warning should be explicit, legible, prominently located, and conspicuous enough to capture the potential user’s attention. Laux went on to state that the warning label on the Control GX product did not meet these criteria. She further opined that had Combe made a warning about the potential for vitiligo and other skin conditions more prominent and conspicuous on the packaging, Moore would not have purchased and, consequently, not used the product. 

Combe challenged both the relevance and reliability of Laux’s testimony under Federal Rule of Evidence 702, Daubert v. Merrell Dow Pharmaceuticals, Inc., and its progeny. Combe argued that Laux’s opinions regarding the adequacy of the Control GX warning labels and their impact on Moore’s purchasing decision were not relevant to the facts of the case. They also questioned the reliability of her methods, contending that she had not provided a discernible methodology for reaching the conclusion that the Control GX warning labels were inadequate or that differently designed warnings would have influenced Moore’s decision to purchase the product. 

Human Factors Expert Witness 

Dr. Lila Fitzgerald Laux has extensive experience in the field of human factors engineering. She pursued her Bachelor of Arts degree from Rice University and a Master of Science degree in Applied Psychology from the University of Southwest Louisiana. Furthering her education, Laux went on to earn a Doctor of Philosophy degree in Industrial Psychology/ Human Factors Engineering from Rice University. She served as the Principal Human Engineer in the Alion Science & Technology, HSI & Decision Support Operation till 2020 and also as a Lead Human Factors Engineer in US West Technologies/Qwest Communications before that. In addition to her work experience, Laux has published research studies in her field of expertise and established herself as a knowledgeable authority in human factors engineering.  

Discussions by the Court 

Combe had argued that Timothy Moore’s acknowledgment during his deposition that he never read the existing warnings on Control GX’s packaging, label, or insert rendered Laux’s opinions on the adequacy of those warnings irrelevant and should be excluded. However, the Moores pointed out that Combe had previously made a similar argument in its motion for summary judgment, which was rejected. 

The Court’s order on the summary judgment motion noted that Moore did not simply admit to failing to read the warning label but described it as nearly illegible. He explained that the text was so small that he couldn’t read it without two pairs of glasses, and it was only legible during the deposition when it was enlarged on a screen. This led to the identification of a genuine issue of material fact regarding the adequacy of the Control GX warning label. Laux’s expert testimony addressed this factual dispute, as she emphasized that effective warning labels should be explicit, legible, prominently located, and conspicuous, and she opined that Combe’s labels did not meet these criteria. 

In response, Combe cited two non-precedential cases as precedent, which rejected expert testimony in failure-to-warn cases when the Plaintiff admitted to not reading the warning labels. However, these cases were deemed inapplicable. In the first case, Gebhardt v. Mentor Corp., the Plaintiff was a physician who did not read the warning label because he was knowledgeable about the device’s risks and benefits based on personal experience, medical literature, and interviews with the device’s inventor. In contrast, Timothy Moore was not a “learned intermediary” regarding the risks of the product and expressed surprise at the severity of the warnings on a shampoo product. 

The second case, Atanassova v. Gen. Motors LLC, appeared more similar on the surface as it excluded the testimony of two expert witnesses, including Laux, on the adequacy of a warning in a car’s owner manual. However, the Court in that case had granted summary judgment on the failure-to-warn claim, reasoning that a different warning label would not have made a difference. In the current case, a genuine issue of material fact existed on this point, making Laux’s testimony highly relevant. 

Combe had argued that Laux’s conclusions regarding the inadequacy of the Control GX warning labels and the potential impact of differently designed warnings on Moore’s purchase decisions lacked a factual basis and amounted to unsupported assertions (ipse dixit). However, contrary to Combe’s characterization of her testimony, Laux did provide a foundation for her expert opinions. 

In her report and deposition, Laux outlined her extensive career in the field of human factors engineering, spanning more than 30 years. During this time, she had engaged in research, reviewed pertinent literature, consulted with corporate clients, and assessed the adequacy of various warning labels. Drawing on her specialized experience, she detailed a three-step process for “developing and evaluating optimal warnings and instructions,” which included: 

  1. Evaluating the user population and identifying potential difficulties or errors in consumer decision-making resulting from human limitations in assessing the risks and consequences associated with product use. 
  1. Assessing product-related factors that influence or shape a consumer’s ability to make informed decisions. 
  1. Evaluating the interaction between the consumer and the product interface, identifying where consumers must make decisions and how the interplay between consumer characteristics and the product interface affects consumer safety behavior. 

After evaluating the Control GX warning label in accordance with the outlined process, Laux arrived at the conclusion that the label was “inadequate to provide the user population with the information they need.” It is important to note that the ultimate determination of the credibility of this testimony and the persuasiveness of her opinion falls to a jury. The Court recognized that the evidentiary standard of reliability is lower than the merits standard of correctness, citing In re Paoli R.R. Yard PCB Litigation

Combe made several other arguments in an attempt to discredit Laux’s testimony. Firstly, they contended that Laux had not examined an actual Control GX box, tube, or insert, but had based her opinions on “blurred photographs” of the product’s warning labels. However, Combe did not claim that these photographs, which were included in the expert report, misrepresented the Control GX warning labels. The Court’s own examination confirmed that the photographs were legible. The issue of whether Laux’s examination of the actual product might have led to a more informed opinion concerned the credibility of her testimony rather than its reliability. 

Secondly, Combe argued that Laux had not compared the Control GX warning labels to those used on other hair dye products, suggesting that this omission rendered her methodology inherently questionable and unreliable. The Court, however, held that such a comparison was inconsistent with the appropriate level of flexibility required by Rule 702. 

Lastly, Combe objected to Laux’s repeated references to the American National Standards Institute (ANSI) standard Z535.4, a voluntary standard that provides guidance to manufacturers on the design of product safety labels. The Court noted that the question under Daubert was not whether an expert’s opinions were correct, but whether they were reliable. Combe did not offer any explanation for why the relevant ANSI standard, even if voluntary, should be considered an unreliable factor when evaluating the adequacy of warning labels. Laux’s testimony clarified that her opinion was not solely based on Control GX’s compliance with ANSI Z535.4 and that her analysis took various factors into account. The accuracy of her analysis was ultimately a matter for the jury to determine. The consideration of a relevant industry standard need not be binding to be reliable, and Combe provided no alternative explanation for why Laux’s reference to it was inappropriate. 


The Court denied the Defendant’s motion to exclude the testimony of Lila Fitzgerald Laux. The Court has not arrived on an outcome for this case since the remaining issues involved in this case still await resolution. 

Key Takeaways:

This case demonstrates that expert witness testimony can be deemed sufficiently reliable under Daubert even if the expert appropriately relies on their experience rather than a rigid comparative methodology. The Court emphasized that the Daubert bar for reliability is flexible and lower than the ultimate correctness standard. Additionally, the case shows that expert testimony can be relevant and helpful to the jury even when factual disputes exist regarding the underlying basis for the opinions. Finally, the Court afforded deference to the jury’s role in determining the credibility and persuasiveness of expert opinions, rather than acting as a “replacement” for the fact finder. So long as reliability and relevance thresholds are met, Courts will likely allow experts to present opinions even if questions exist that go to the weight of the testimony. 


One response to “Evidentiary Standard of Reliability is lower than the merits standard of correctness;Court admits the testimony of Human Factors Expert Witness regarding the adequacy of the product’s warning labels in this failure-to-warn suit”

  1. informative post

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