Once discovery closed in the Hughes litigation, Kia moved to exclude the testimony of plaintiff's causation expert, arguing that plaintiff's expert was "not the product of reliable methodology and it did not fit the evidence in the case." Id. at *16. The district court granted both Kia's motion to exclude testimony and for summary judgment. On appeal, the Eleventh Circuit considered the exclusion of plaintiff's expert testimony under an abuse of discretion standard. Id. at *21, citing Gen. Elec. Co. v. Joiner, 522 U.S. 136, 142-43, 118 S. Ct. 512, 517 (1997)(holding that the "standard of review requires that we defer to the district court's evidentiary ruling unless that ruling is 'manifestly erroneous.'")
Next, the court looked to Federal Rule of Evidence 702, which provides:
A witness who is qualified as an expert by knowledge, skill, experience, training or education may testify in the form of an opinion or otherwise if:
(a) the expert's scientific, technical, or other specialized knowledge will help the trier of fact to understand the evidence or to determine afact in issue;
(b) the testimony is based on sufficient facts or data;
(c) the testimony is the product of reliable principles and methods;
(d) the expert has reliably applied the principles and methods to the facts of the case.
Applying Rule 702 and the Supreme Court's decision in Daubert v. Merrell Dow Pharm., Inc., 509 U.S. 579, 113 S. Ct. 2786 (1993), district courts are viewed as gatekeepers responsible for ensuring "that speculative, unreliable expert testimony does not reach the jury." Hughes at *22, quoting McCorvey v. Baxter Healthcare Corp., 298 F.3d 1253, 1256 (11th Cir. 2002). Whether an expert's testimony is reliable depends on the "particular facts and circumstances of the particular case." Kumho Tire Co. v. Carmichael, 526 U.S. 137, 152, 119 S. Ct. 1167, 1176 (1999).
Next, the Hughes court looked at the three requirements that an expert must meet before the expert's testimony may be admitted:
First, the expert must be qualified on the matter about which he intends
to testify.City of Tuscaloosa v. Harcros Chemicals, Inc., 158 F.3d 548,
562 (11th Cir. 1998).
Second, he must employ reliable methodology. Id. Third, the expert's testimony must be able to assist the trier of fact through the application of expertise to understand the evidence or fact in issue. Id. With respect to whether an expert's methodology is reliable, we look to a number of factors, including
(1) whether the methodology can be and has been tested,
(2) whether the theory or technique has been subjected to peer review,
(3) the known or potential rate of error of themethodology employed, and (4) whether the methodology is generally accepted.Hughes at*23, citing Daubert, 509 U.S. at 593-94.
The Eleventh Circuit in Hughes held that the district court did not abuse its discretion by excluding the expert's testimony for being unreliable. Id. at 24. According to the court, plaintiff's expert claimed he relied on the evidence of the case, his experience and relevant literature and that his report was based on scientific method. Id. The district court, however, found that plaintiff's expert did not explain how he tested his hypothesis to support his conclusions. During deposition, plaintiff's expert admitted that his methodologies required he consider the physical forces (referred to as "lateral delta v") and their effect on the decedent. Id. at 19. Yet the district court found that the expert failed to consider the lateral delta v involved in the collision and that this omission "demonstrated a failure to follow his stated methodology." Id.
The district court also rejected plaintiff's expert testimony due to the expert's "failure to attempt to falsify his conclusions." Id. The decedent died after sustaining multiple impacts following an initial collision with a tractor trailer. The district court faulted plaintiff's expert for not "know[ing] enough about the other impacts sustained after the initial impact with the tractor trailer to determine whether [the decedent] suffered her fatal brain injury at any other point in the sequence of events." Id. at *19-20, fn. 10. According to the district court, plaintiff's expert's failure to test his hypothesis, including following his stated methodologies, along with the expert's failure to falsify his conclusions rendered the testimony inadmissible under Daubert. On appeal, the Eleventh Circuit agreed, finding the expert based his findings on scientific method, yet not being able to show how he tested his hypothesis to support his conclusions. Id. at 24.
It is helpful to understand Hughes as it provides a current look at how the Eleventh Circuit approaches Daubert challenges. As the Hughes court stated, "something doesn't become scientific knowledge just because it's uttered by a scientist; nor can an expert's self-serving assertion that his conclusions were derived by the scientific method be deemed conclusive." Id. at *26, citing McDowell v. Brown, 392 F.3d 1283, 1299 (11th Cir. 2004) and quoting Fed. R. Evid. 702, advisory committee's note, 2000 amendment (The trial court's gatekeeping function requires more than simply taking the expert's word for it.") For plaintiffs, Hughes reminds us that plaintiff's experts (as well as defense experts) should state the relevant scientific method which he or she adhered to and how such method is accepted within their scientific community. Experts may also want to challenge their own conclusions to show alternative findings are not valid.