Happy birthday, Hans Mattson. Did you, dear reader, forget? No worries. Mattson was born in Sweden in 1832, played a key role in Swedish settlement in Minnesota, served in the U.S. Civil War, and was consul to India. It’s been a long time since he blew out any candles, so your oversight will offend nobody. But Mattson’s birthday reminds us of how much we like Minnesota, with its pleasant people, strange accents, Bob Dylan, Kevin McHale, law school classmate Senator Amy Klobuchar, Prince, Morris Day, and pro football team that is often good, but never good enough.

Last March, we reported on a Minnesota trial court decision that was more than good enough. The court excluded a plaintiff expert’s opinion because it was not generally accepted. We liked that opinion. It turns out that the Minnesota appellate court did, too, and today we will share that affirmance with you. The case is In re: 3M Bair Hugger Litigation, 2019 WL 178498 (Minn. Ct. App. Jan. 14, 2019). This is the Bair Hugger litigation, which has a backstory straight out of Dostoyevsky or the most tawdry soap opera. The Bair Hugger is a forced-air warming device (FAWD) used to maintain patients’ normal body temperature during surgery. The inventor of the device ran into some legal problems and left the company. He then invented a rival device, which he charmingly called the Hot Dogger, and proceeded to compete with his former product. His notion of competition was a bit brutal. He did not simply claim that the Hot Dogger was better than the Bair Hugger. Instead, he claimed that the Bair Hugger increased the risk of surgical-site infection (SSI). The FDA investigated the claims that the Bair Hugger increased the risk of bacterial contamination and rejected them.

Then the inventor (whose name is Augustine) funded a study purporting to find an association between the Bair Hugger and increased SSIs. One of the study’s authors, a former employee of Augustine, testified that “[t]he study does not establish a causal basis” and characterized it as marketing rather than research. In 2017, the FDA sent a Safety Alert to healthcare providers “reminding [them] that using thermoregulation devices during surgery, including [FAWDs], ha[s] been demonstrated to result in less bleeding, faster recovery times, and decreased risk of infection for patients”; advising them that “[a]fter a thorough review of available data, [the FDA was] unable to identify a consistently reported association between the use of [FAWDs] and [SSIs]”; and recommending “the use of thermoregulating devices (including [FAWDs]) for surgical procedures. This is all very good news for the Bair Hugger and very bad news for its competitors.

Did Augustine confess error? He did not. Did Augustine take this setback lying down? He did not. He supported lawsuits against the Bair Hugger. Those lawsuits depended on medical experts who linked the Bair Huggers to infections, even though said experts had never previously studied the efficacy of FAWDs or published peer-reviewed articles relevant to the claims in this litigation and none of whom claimed that their general-causation opinions were generally accepted within the relevant scientific community. The Bair Hugger folks quite rightly moved to preclude these threadbare opinions. The trial court excluded the testimony of appellants’ experts and consequently granted responded summary judgment with respect to general causation. That is the opinion we reported on last year and that is the opinion upheld by the court of appeals. Oddly, the last word of the appellate opinion is the usual “Affirmed.” Having watched Fargo at least ten times, we would have thought the court would have concluded with a “You betcha!”

The issue turned on application of Minn. R. Evid. 702, which governs expert testimony. When you see “702” and “experts,” you might think of Federal Rule of Evidence 702 and the Daubert requirements. But Minnesota does not follow Daubert. Rather, Minnesota calls itself a “Frye-Mack state.” Frye is the old “general acceptance” theory trotted out a long time ago and which now finds itself ousted from the federal courts and most state courts. But the Frye theory is alive and well in the land of ten thousand lakes. The key Minnesota case is called Mack. Get it? Under the Frye-Mack test, if an expert’s opinion involves a “novel scientific theory,” the proponent must establish “that the underlying scientific evidence is generally accepted in the relevant scientific community.” The Minnesota appellate court reviewed de novo whether the underlying scientific evidence was generally accepted in the relevant scientific community. (Federal appellate courts reviewing Daubert decisions usually employ a less rigorous abuse of discretion standard.)
The appellants tried to escape the Frye-Mack general acceptance test by arguing that the science used here was not “novel” within the meaning of Minn. R. Evid. 702. Nice try. But the court held that Minn. R. Evid. 702 pertains to “novel scientific theory,” not novel science. The fact that air and particulate movement is not a new science does not mean that appellants’ premise, i.e., that FAWDs increase the risk of SSIs, is not a novel scientific theory. So much for that first line of attack. (This “novel scientific theory” issue is quite different from a typical Daubert analysis.)

Now on to the main feature.

The appellants repeated their argument from below that Minn. R. Evid. 702 does not require a showing that “proof of the expert’s ultimate opinion” is generally accepted; instead, it requires only a “showing that the tools employed by the expert[s] in reaching their opinion [i.e., the experts’ methodologies] have gained general acceptance.” The appellate court agreed with the trial court that Minn. R. Evid. 702 is not restricted to novel methodologies; it refers to “opinion or evidence involv[ing] novel scientific theory” for which “the underlying scientific evidence is generally accepted.”

The appellate court deferred to the assessment of the relevant scientific community rejecting appellants’ novel scientific theory (that’s the swell, easy thing about the Frye test – it is really about deferring to scientific consensus) and concluded that there is no demonstrated causal relationship between FAWDs and increased risk of SSI. Accordingly, the appellate court affirmed the district court’s decision to exclude appellants’ experts’ evidence. It also affirmed the trial court’s summary judgment as to general causation. It occurs to us that the holding that regardless of methodology, your result is crazy and therefor excludable, indicates that a properly enforced “general acceptance” based exclusionary rule can be as good as, or even better than, Daubert.

In any event, this Bair Hugger opinion is useful and nice. Minnesota nice.