Not even three weeks ago, back on July 28, we discussed the court’s rigorous application of Daubert in excluding expert medical causation opinions in Smith v. Terumo Cardiovascular Sys. Corp., a federal case in the district of Utah. The plaintiff had undergone a heart valve replacement surgery. As is typical, the surgery required use of a perfusion heart/lung bypass machine. At some point, the machine stopped working for 10-11 minutes. The patient died of a heart attack 11 months later. The decedent’s heirs brought suit against various defendants, including the manufacturer of the heart/lung bypass machine.

In the opinion we discussed on July 28, the court excluded most of the opinions of a cardiologist tendered by plaintiffs as an expert on causation. That expert was refreshingly candid in acknowledging that he could not say for sure that the heart attack was caused by any machine malfunction, though he thought the malfunction probably played some role. Because the cardiology expert himself acknowledged an “analytical gap,” because he was plainly unqualified to render opinions on neurologic issues, and because he relied on diagnostic methods that were not generally accepted, the court limited the cardiologist expert’s testimony to an opinion that the decedent’s heart was injured during the valve replacement surgery. Not nothing, but not much, either.

Today, we discuss the same litigation with the same Daubert issue with a different expert but a similar result. Smith v. Terumo Cardiovascular Sys. Corp., 2017 U.S. Dist. LEXIS 124866 (D. Utah August 7, 2017), involves a different plaintiff expert proffered to opine on medical causation. This expert was a licensed perfusionist. No one disputed that this expert could opine on the standard of care applicable to perfusionists and facilities where perfusion services are offered. What was disputed was whether the expert could testify about a potential defect in the heart/lung bypass machine that may or may not have exhibited during the surgery in question. The expert was going to testify that a defect in the machine’s air bubble detection system led to the inadvertent 10-11 minute shutdown during the surgery. The expert primarily relied upon a recall of the heart/lung bypass machine that occurred almost two years after the decedent’s surgery.

The court begins its analysis in the right place with Federal Rule of Evidence 702. Then we get a paragraph on how the law favors admissibility of expert testimony. We wince whenever we read about such a presumption, anticipating judicial abdication of the gatekeeping function. But that was not the case here. Rather, the court carefully assessed the expert’s qualifications and found them wanting. The expert knew all about perfusion and how to operate the heart/lung bypass machine, but that does mean he possessed the requisite expertise to analyze the design and technical functionality of the machine. The defense deposed the expert, and did a nice job of bringing out the expert’s lack of expertise in mechanical engineering or design. The existence of the product recall might have been suggestive, but to explain why the recall was issued, and why the reason for the recall also accounted for the device’s stoppage during the surgery, required precisely the sort of engineering or design expertise that was lacking.

Even aside from the threshold issue of qualifications, the court concluded that the expert’s opinions were unreliable. The expert’s report disclosed reliance on depositions, reports, system logs, and medical records. That sounds pretty good. But the expert never explained how the facts he reviewed, including the device recall, added up to a defect in the device that prompted the stoppage during the surgery. The expert theorized that the perfusion system might have issued a false alarm, which then resulted in the stoppage, but nothing concrete supported that theory. Indeed, the expert admitted in deposition that no one could explain exactly how the alleged malfunction occurred. (More refreshing candor!) The court seized upon something that plaintiffs usually emphasize: the failure to test. The plaintiff’s expert had never attempted to test his defect theory. Testing, of course, is one of the key Daubert factors. In this case, the expert’s failure to test his theory kept him in the realm of speculation, and kept his opinions away from the jury.