In Davis v. Honeywell International Inc. (filed 3/3/16, B256793), the admissibility of evidence going to the burden on a plaintiff in an asbestos-related cancer case to prove legal cause, as was addressed by the California Supreme Court in Rutherford v. Owen-Illinois, Inc.(1997) 16 Ca.4th 953, is clarified in light of the trial court’s “gatekeeper” role when it comes to expert evidence as described in the high court’s opinion of Sargon Enterprises, Inc. v. University of Southern California (2012) 55 Cal. 4th 747. (See this blog’s November 30, 2012 article on Sargon.) The opinion of the Court of Appeal, Second Appellate District, Division Four, is also instructive more generally on the question of admissibility of scientific evidence.
The Davis case involved the lawsuit of the survivor of Sam Davis who brought a wrongful death action against defendant Honeywell alleging that his exposure in the 1960’s and 1970’s to asbestos in Bendix brake linings, manufactured by defendant, was a substantial factor in contributing to his risk of developing mesothelioma which eventually caused his death. From about 1964 until 1979, Davis did automotive repairs including on average 1 or 2 brake jobs a day wherein he would sand each lining for 1 to 2 minutes, producing dust fibers he would inhale. The evidence at trial additionally noted he did home remodeling during the same time period two or three times a month that caused him to inhale the dust caused by the pre-mixed joint compound powder and the sanding of the post-mixed “mud.”
During jury trial, plaintiff’s counsel was permitted by the trial judge, over defendant’s objection, to present the testimony of medical experts who discussed several studies and scientific articles supporting their determination that upon review of Davis’ medical records and level of inhalation exposure to asbestos fibers incurred from the brake work, they were of the opinion that these low doses of such cumulative exposure were substantial contributing factors in Davis’s developing mesothelioma many years after that exposure. Defendant presented its scientific and medical experts who offered refutation of this “every exposure” theory, and concluded there was no association between Davis’ employment as a mechanic and the risk of mesothelioma.
The jury found liability and awarded $2 million in damages; Honeywell was allocated responsibility for 85% of this total. On appeal, defendant’s primary contention was that plaintiff’s expert testimony based on an “every exposure” theory should have been excluded under Sargon. The Court of Appeal disagreed, finding plaintiff’s theory is the subject of legitimate scientific debate, thus it was for the jury to resolve the conflict between the every exposure theory and any competing expert opinions; the trial court did not abuse its discretion in admitting plaintiff’s expert testimony and evidence. The judgment was affirmed.
To me, the most critical part of this analysis is that even though the Sargon court found it appropriate for the trial court to exclude the expert testimony in that case as being wholly unreliable, the overriding principle to be applied is as follows: “The [trial] court does not resolve scientific controversies. Rather, it conducts a ‘circumscribed inquiry’ to ‘determine whether, as a matter of logic, the studies and other information cited by experts adequately support the conclusion that the expert’s general theory or technique is valid’. . . The goal of the trial gatekeeper is simply to exclude ‘clearly invalid and unreliable’ expert opinion.” (Davis court quoting Sargon at page 773.)
I would say that Davis’s take on Sargon offers encouragement to those wishing to offer scientific or medical expert testimony at trial so long as there is a showing of sufficient logic from available data and studies that a reasonable jury may find the evidence valid, even if the theories upon which the expert conclusions are based are disputed in the expert community.