The nature of advocacy makes it hard sometimes for lawyers to focus solely on the outcome and the bottom line result. How a court gets there may not matter much to the prevailing party in the dispute as they celebrate the win, but it may have an impact on later cases. A recent example is the opinion in Burton et al. v. E.I. DuPont de Nemours and Co., Inc., 2021 WL 1422814 (7th Cir. Apr. 15, 2021). The court found the winner’s circle, but it dented the car a bit along the way.
[Disclosure/disclaimer: The author filed an amicus brief in support of defendants in the case.]
Burton was an appeal in three consolidated bellwether lead paint exposure cases in the Eastern District of Wisconsin. Applying Wisconsin’s “risk contribution” rule, a version of market share liability for defective fungible products, the court of appeal reversed a jury verdict finding three manufacturers of white lead carbonate liable to all three plaintiffs on underlying theories of strict liability failure-to-warn and general negligence. The court of appeal rendered judgment for one defendant, and remanded for a new trial as to the two others. The court addressed several recurring product liability issues, for the most part favorably. But for present purposes, we examine the fly we see in the ointment: the court’s mishandling of the district court’s gatekeeping rulings.
Plaintiffs claimed they sustained brain damage from residential exposure to lead paint chips and dust residue as children. To establish the fact, cause, and extent of their injuries, they called two experts: neuropsychologist Dr. Trope and pediatrician/toxicologist Dr. Besunder.
Dr. Trope interpreted the “patterns of performance” in plaintiffs’ cognitive tests, discrepancies in their various functional domains, to conclude that they had developed brain damage. This was simply a snapshot of plaintiffs’ present cognitive function; the alleged lead exposures had occurred decades earlier.
Perhaps a sufficient foundation could be laid for this opinion from a qualified expert, but Dr. Trope was not that, and she was unable to cite any objective basis for her interpretation of the “patterns” she saw in the testing results. No authoritative or consensus objective source supported her methodology; no recognized professional standards or guidelines spelled out how to use discrepancies in domain performance patterns to detect brain damage. Individuals often display cognitive strengths and weaknesses in different areas of function, for a wide variety of reasons. Accordingly, Dr. Trope’s opinion, untethered to any objective standards limiting the subjectivity of her analysis, appears to have violated Daubert’s distinction between admissible “scientific knowledge” and inadmissible “subjective belief” and “unsupported speculation,” and the overall requirement of a reliable and recognized scientific methodology. Medical diagnostic and causation opinions based primarily on the expert’s impressionistic judgments and personal opinion are routinely excluded under Rule 702, because they defy a hallmark of the scientific method: verification or falsification. That’s why we ask whether the testimony is “testable.”
The court of appeals entirely ignored the subjectivity problem and held that Dr. Trope was properly allowed to testify that plaintiffs had developed brain damage.
On causation, the court observed that plaintiffs had not offered Dr. Trope on the subject. Rather, defendants had purportedly elicited on cross-examination, over plaintiffs’ objection, her opinion that childhood lead exposure caused plaintiffs’ brain damage. That characterization is puzzling. It would suggest defendants’ assignment of error would have been waived or invited. But Plaintiffs never argued waiver, nor did the court consider it, and both plaintiffs and the district court cited Dr. Trope’s testimony as support for the jury’s causation finding. And Dr. Trope’s causation opinion raised obvious qualification, reliability, and foundation issues. The court of appeal dodged them all, finding instead that any error in admission was harmless because Dr. Besunder’s causation testimony had been properly admitted.
Dr. Besunder had testified that each plaintiff had sustained a brain injury caused by lead exposure producing an IQ loss of “at least 10 points.” The court of appeals found he had properly based his specific causation opinion on comparison of plaintiffs’ patterns of brain function compared to the patterns described in some studies of childhood lead poisoning, and the absence of alternative causes in their medical records.
The court failed to mention that
- Plaintiffs disavowed Dr. Besunder as a “causation” witness at all, describing instead his testimony about the extent of their damage (the IQ points);
- Besunder had relied on epidemiology studies to opine on individual causation; and
- His patterns of functioning analysis derived from Dr. Trope’s unreliable analysis which, again, was based on a snapshot of present function.
The court of appeal nevertheless affirmed admission of the “causation” opinion, entirely ignoring the mismatch between population studies and individual causation. Epidemiology is capable of proving, at most, that lead exposure under certain circumstances is capable of causing brain injury and variable loss of IQ – not that it did so.
The court did, however, sustain defendants’ challenge to Dr. Besunder’s extent of damage opinion. His methodology – taking correlations between blood lead levels and IQ deficits from the epidemiology studies, averaging them, and then applying the averages to the blood levels recorded in plaintiff’s medical records – was “unprecedented.” The court also recognized that Dr. Besunder had no baseline pre-exposure performance data, and he had not examined the plaintiffs.
A mixed bag, at best, on Daubert. The headline remains the court’s reversal and holding that the district court had overextended the troublesome risk contribution theory to reach decades of sales of paint that were not subject to the doctrine, and that the liability verdicts were legally or evidentially unsupported. One defendant escaped liability altogether, and the other won a do-over with a less tilted playing field. But for the rest of us, there is also a poor precedent on a few Daubert issues to grapple with.