Opinion ID: 174941
Heading Depth: 3
Heading Rank: 2

Heading: Speculation and Gaps in the Testimony

Text: The majority finds that Dr. Carlini's testimony was speculative, stating without support that the testimony was no more than a hypothesis, [and is] thus not `knowledge,' nor is it `based upon sufficient facts or data' or the `product of reliable principles and methods ... applied ... reliably to the facts of the case.' ( Ante at 670.) I disagree that Dr. Carlini's testimony was speculative. Based on the record, it seems clear that Dr. Carlini was relying upon scientific studies which tested the causal connection between manganese exposure and Parkinson's Disease. Furthermore, the district court was exercising its broad discretion when it found that Dr. Carlini's methodology was reliable and consistent with the diagnostic methods used by other experts in the case. It seems incredible that the majorityexercising a standard of review that seems closer to de novo than abuse of discretion, and without the benefit of having sat through the hearings and seen the expertsfinds Dr. Carlini's testimony to be speculative. The majority also cites gaps in Dr. Carlini's testimony as a reason to reverse the district court. ( Ante at 670-71.) However, the majority's newly-minted requirement that scientific testimony must be without flaws or gaps and have no unprovable inferences or assumptions runs counter to any reasonable understanding of how scientific truth is reached. Scientists disprove things. In the process they filter error from theories and methodology, but they do not prove that the surviving methodologies those that are left standing or those that are changed to correct errors are valid. Jan Beyea & Daniel Berger, Scientific Misconceptions among Daubert Gatekeepers: The Need for Reform of Expert Review Procedures, 64 LAW & CONTEMP. PROBS. 327, 337 (2001). Furthermore, the theories that survive testing still have components that have never been tested, contain subjective elements, and require that reasonable inferences be made if they are to be used in real world examples. Id. At least one other Circuit court has found that to the extent that [the defendant] asserts there were gaps or inconsistencies in the reasoning ... such arguments go to the weight of the evidence, not its admissibility. Campbell v. Metro. Prop. and Cas. Ins. Co. 239 F.3d 179, 186 (2d Cir.2001) (the trial court did not abuse its discretion in admitting expert testimony that plaintiffs were suffering from lead poisoning). Indeed, the most cherished of scientific truths are the subject of constant refinement and are frequently overturned by subsequent science. For instance, the 42-year consensus that DNA alone determines heredity was later dethroned as a universal principle, albeit after the 1994 article by Black et al. was published. Id. at 335. In fact, simultaneously accepted scientific principles are sometimes incompatible, and thus, might fare badly under a strict Daubert application. Imagine Euclid testifying in a modern day Daubert proceeding: `Professor Euclid, I understand that one of your postulates is that parallel lines do not meet at infinity. Can you prove this to be true? Have you ever tested this? Isn't it also true that Professor Einstein has proven that your geometry doesn't work in the presence of gravity?' Id. at 335 n. 42. While the district court must necessarily draw lines, we must use caution in demanding the type of finality from science that we have come to expect in law. This is especially true when considering cases of newer scientific studies. It seems to me an overly harsh test at the admissibility level to insist upon testimony with no gaps, when the science itself may be incapable of absolute proof. Do malfeasing defendants get a free pass on the first few victims because there is not yet a sufficient sample set to create scientific studies with no discernable gaps? Do we tell the early victims, I'm sorry, you had the misfortune of getting sick too soon, and send them home? The fact that scientists have not reached consensus regarding medical causation does not render reliance on a scientist's theory improper expert testimony, particularly when, as in this case, the expert is relying on studies that appear to have been conducted using standard methodology. Rather, those differences should go to the weight that a jury should give an expert's testimony. See Best v. Lowe's Home Centers, Inc., 563 F.3d 171, 182 (6th Cir.2009) (finding that admissibility under 702 does not require perfect methodology.... Any weakness in [a competent, intellectually rigorous physician's] methodology [in identifying the most likely cause of the plaintiff's injury] will affect the weight that his opinion is given at trial, but not its threshold admissibility.). In cases where the state of scientific consensus is difficult to determine, we must defer to the district court. The district court has the distinct advantage of having heard all the experts testify and can weigh the reliability of a given expert's testimony against others more easily than we can. Our valuations of complicated medical expert issues such as these are made out of context and are therefore more likely to suffer flaws. Because Dr. Carlini relied on scientific methodology used by other experts in his field, see infra at 28, I do not believe that the district court abused its discretion in admitting his testimony. The district court's determination that Dr. Carlini's methodology was sufficiently reliable was certainly not clearly erroneous, so the testimony was admissible. What weight to grant his testimony was a question for the jury, not an appellate court sitting far removed from the trial. Because the majority has not demonstrated that the district court abused its discretion, it errs in reversing the district court's decision.