Litigants may soon have additional guidance when assessing and attacking the qualifications of experts who seek to testify on lesser-known but developing areas of science under Michigan Rule of Evidence 702.
In Walters v Falik, the Michigan Supreme Court granted oral arguments on a handful of evidentiary issues pertaining to an expert’s analysis of the cause of a dental patient’s autoimmune disease. This personal injury appeal followed a patient’s accidental exposure to phosphoric acid, a caustic chemical substance.
In Walters, the patient believed she was using a tooth whitening solution at night that was provided by her dentist’s office. However, the patient went to bed with a tooth etching solvent instead, which contained phosphoric acid and is only generally intended for short applications to teeth during dental restoration appointments. Soon after the application of the product, the patient experienced burning sensations, blockage in her ear, major reported sinus issues, and eventually an autoimmune disease called Wegener’s Granulomatosis.
In support of her claims, the patient in Walters submitted purported scientific expert testimony that the misapplied phosphoric acid caused her autoimmune disease. However, Wegener’s Granulomatosis is not a well-known disease. For example, actual human tests proving (or disproving) that phosphoric acid caused her disease were unavailable to support the “expert” opinion on causation because, per the patient’s expert, “there would be no studies in which a person was experimentally exposed to phosphoric acid, as to conduct such testing would be unethical.” This appeal ultimately followed the trial court’s exclusion of the testimony, asserting various deficiencies in the “expert” opinion.
Walters raises important questions, such as whether a scientific expert’s testimony is admissible where the science-based opinion is not generally accepted within the relevant expert community – as was the case in Walters. The Michigan Supreme Court may also provide guidance on the amount of peer-reviewed medical literature required for a scientific expert’s opinion. Such considerations were the focal point of the Court’s 2016 ruling in Elher v Misra, which rejected an expert’s opinion due to such vulnerabilities. The expert in Walters arguably shares these vulnerabilities but implicates a concern on what, if any, “expert” scientific testimony can be presented in a lesser-known but developing field like many of the sciences pertaining to autoimmune diseases.
We will continue to monitor and report developments as the case proceeds.