In an interesting series of cases, an expert witness claimed to have arrived at the specific causation of plaintiff’s stomach cancer by using “Bayesian probabilities which consider the interdependence of individual probabilities.” Courtesy of counsel in the cases, I have been able to obtain a copy of the report of the expert witness, Dr. Robert P. Gale. The cases in which Dr. Gale served were all FELA cancer cases against the Union Pacific Railroad, brought for cancers diagnosed in the plaintiffs. Given his research and writings in hematopoietic cancers and molecular biology, Dr. Gale would seem to have been a credible expert witness for the plaintiffs in their cases.[1]
The three cases involving Dr. Gale were all decisions on Rule 702 motions to exclude his causation opinions. In all three cases, the court found Dr. Gale to be qualified to opine on causation, which finding is decided by a very low standard in federal court. In two of the cases, the same judge, federal Magistrate Judge Cheryl R. Zwart, excluded Dr. Gale’s opinions.[2] In at least one of the two cases, the decision seemed rather straightforward, given that Dr. Gale claimed to have ruled out alternative causes of Mr. Hernandez’s stomach cancer. Somehow, despite his qualifications, however, Dr. Gale missed that Mr. Hernandez had had helicobacter pylori infections before he was diagnosed with stomach cancer.
In the third case, the district judge denied the Rule 702 motion against Dr. Gale, in a cursory, non-searching review.[3]
The common thread in all three cases is that the courts dutifully noted that Dr. Gale had described his approach to specific causation as involving “Bayesian probabilities which consider the interdependence of individual probabilities.” The judicial decisions never described how Dr. Gale’s invocation of Bayesian probabilities contributed to his specific causation opinion, and a careful review of Dr. Gale’s report reveals no such analysis. To be explicit, there was no discussion of prior or posterior probabilities or odds, no discussion of likelihood ratios, or Bayes factors. There was absolutely nothing in Dr. Gale’s report that would warrant his claim that he had done a Bayesian analysis of specific causation or of the “interdependence of individual probabilities” of putative specific causes.
We might forgive the credulity of the judicial officers in these cases, but why would Dr. Gale state that he had done a Bayesian analysis? The only reason that suggests itself is that Dr. Gale was bloviating in order to give his specific causation opinions an aura of scientific and mathematical respectability. Falsus in duo, falsus in omnibus.[4]
[1] See, e.g., Robert Peter Gale, et al., Fetal Liver Transplantation (1987); Robert Peter Gale & Thomas Hauser, Chernobyl: The Final Warning (1988); Kenneth A. Foon, Robert Peter Gale, et al., Immunologic Approaches to the Classification and Management of Lymphomas and Leukemias (1988); Eric Lax & Robert Peter Gale, Radiation: What It Is, What You Need to Know (2013).
[2] Byrd v. Union Pacific RR, 453 F.Supp.3d 1260 (D. Neb. 2020) (Zwart, M.J.); Hernandez v. Union Pacific RR, No. 8: 18CV62 (D. Neb. Aug. 14, 2020).
[3] Langrell v. Union Pacific RR, No. 8:18CV57, 2020 WL 3037271 (D. Neb. June 5, 2020) (Bataillon, S.J.).
[4] Dr. Gale’s testimony has not fared well elsewhere. See, e.g., In re Incretin-Based Therapies Prods. Liab. Litig., 524 F.Supp.3d 1007 (S.D. Cal. 2021) (excluding Gale); Wilcox v. Homestake Mining Co., 619 F. 3d 1165 (10th Cir. 2010); June v. Union Carbide Corp., 577 F. 3d 1234 (10th Cir. 2009) (affirming exclusion of Dr. Gale and entry of summary judgment); Finestone v. Florida Power & Light Co., 272 F. App’x 761 (11th Cir. 2008); In re Rezulin Prods. Liab. Litig., 309 F.Supp.2d 531 (S.D.N.Y. 2004) (excluding Dr. Gale from offering ethical opinions).
