Skip to Content

Expert Testimony Held Admissible Under Daubert

June 27, 2012

Ledbetter v. Blair Corp., 2012 WL 2464000 (M.D. Ala. June 27, 2012).


Under federal law, where an expert relies on multiple sources detailing a person’s medical history, the expert’s opinion regarding drug impairment may be admissible despite the expert’s lack of clinical observations of the effects of the drugs on the specific person. Flaws regarding the expert’s methodology go to the weight of the expert’s opinion, rather than to its admissibility.


This products liability case arises out of the death of Annie Thrash, who was wearing a chenille robe that ignited and fatally burned her. Thrash’s estate sued Blair, LLC (“Blair”), which had marketed and sold the chenille robe. The parties retained experts that disagreed about the fire’s origin and the cause of Thrash’s death. The plaintiff’s experts theorized that the robe caught fire as Thrash prepared breakfast, and Thrash fled the kitchen, fell to the floor of the living room, and ignited a sofa. The plaintiff claimed the robe was highly flammable and contained a design defect that made it more susceptible to cooking fires. In contrast, the defense experts opined that it could not be proven that the fire started in the kitchen rather than at the sofa. The defense experts also opined that Thrash’s ability to escape was hindered by her legal use of certain drugs. The parties filed cross-motions to exclude each other’s experts as inadmissible under Federal Rule of Evidence 702 and Daubert v. Merrell-Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993).


The court allowed testimony regarding Thrash’s impairment and the potentially negative effect of postmortem redistribution (“PMR”) on postmortem drug testing. The court also allowed expert testimony about carbon monoxide concentrations based on the Stewart and Coburn-Forster-Kane (“CFK”) equations and the Fire Dynamics Simulator (“FDS”).


The court rejected the plaintiff’s argument that expert testimony is unreliable under Daubert where the expert bases his or her opinion on the concentration of drugs in postmortem blood without the benefit of clinical observations. The court found the expert’s opinion was reliable because, contrary to the plaintiff’s argument, the expert’s opinion was based on his education, practice, and experience as well as multiple sources including prescription records, medical records, depositions of treating physicians, the fire department’s report, the autopsy report, postmortem drug concentrations, the ranges of therapeutic blood concentrations for the drugs at issue, and a chronology of Thrash’s medical history. The court explained that flaws in the expert’s methodology, including the lack of clinical observations, were proper subjects for cross-examination because these flaws went to the weight rather than the admissibility of the testimony.

The court also rejected the defense’s challenge to a plaintiff’s expert’s opinion that PMR could not accurately portray antemortem drug concentrations. PMR is the redistribution of drugs in the blood after death, which can result in different levels of drug concentration in the organs, tissue, or blood vessels, as compared to levels in circulating blood. The court noted that the parties did not dispute that PMR was a valid scientific theory. Further, the peer-reviewed literature showed a consensus on scientifically valid techniques that mitigated the effects of PMR, and this case involved one such technique (using peripheral blood for testing).

In addition, The court allowed opinion testimony regarding an expert’s analysis of carbon monoxide levels based on the CFK equations and the FDS. The court explained that the CFK equation and the FDS Manual were adopted by a National Fire Protection Association publication that the parties did not dispute was an accepted methodology for investigating and analyzing fires. The court disagreed with the defense’s argument that the expert’s reliance on an article about the burning behavior of curtains and draperies warranted exclusion. The court stated that the expert’s reliance on the article was an appropriate issue for cross-examination.