Correlation Equals Causation? Potential Hurdles For Defendants In Daubert Motions Against Causation Experts

• Published date: 05 October 2021
• Subject Matter: Litigation, Mediation & Arbitration, Trials & Appeals & Compensation
• Law Firm: Butler Snow LLP
• Author: Butler Snow LLP

Kovach v. Wheeling & Lake Erie Ry. Co., No. 3:18-CV-02826-JGC, 2021 WL 3774900 (N.D. Ohio Aug. 25, 2021) encourages defense attorneys to challenge experts with tactics other than Daubert, as the court avoided excluding plaintiff's causation expert.

Mr. Kovach worked at the Wheeling and Lake Erie Railway Company ("Wheeling") for twenty-five years. While at Wheeling, Mr. Kovach was exposed to various substances including daily contact with diesel fuel. Just two years after his retirement, Mr. Kovach was diagnosed with non-Hodgkin's lymphoma; he died shortly thereafter.

Mr. Kovach's widow brought the action, alleging that Wheeling negligently exposed Mr. Kovach to toxic substances which caused his cancer. Wheeling moved to exclude plaintiff's causation expert, Dr. Arthur Frank. Dr. Frank opined that Mr. Kovach's exposure to diesel fuel, kerosene, exhaust, pesticides, and herbicides significantly contributed to Mr. Kovach developing cancer.

The court immediately noted its reluctance to exclude experts, encouraging litigants to instead undermine experts through cross-examination or contrary evidence, among other advocacy tactics. Still, Wheeling sought to exclude Dr. Frank's opinions on general and specific causation, arguing that Dr. Frank used unreliable sources.

Wheeling argued that Dr. Frank failed to establish general causation because he used sources showing benzene's correlation with cancer, not that benzene caused cancer. However, experts do not need to rely on research showing direct cause-and-effect relationships'associational sources sufficiently point to general causation. Importantly, the court suggested that it can still exclude experts relying on associations if those experts have other deficiencies, such as failing to review medical records, fact depositions, or available exposure data.

Following Dr. Frank's conclusion that diesel and kerosene contributed to Mr. Kovach's cancer, Wheeling argued that Dr. Frank's sources were inapplicable because they dealt with benzene, not diesel or kerosene. Considering that diesel and kerosene contain benzene, Dr. Frank's focus on benzene was permissible. Again, the court advised Wheeling to question Dr. Frank's sources through cross-examination instead of excluding Dr. Frank's opinion outright.

As for specific causation, Wheeling argued that Dr. Frank should not have solely relied upon a letter from plaintiff's counsel to craft his opinion; the letter outlined Mr. Kovach's work responsibilities and chemical...