75 F.4th 967
8th Cir.2023Background
- James Lancaster worked for BNSF for 33 years; diagnosed with lung cancer in 2016 and died in 2018.
- Rebecca Lancaster sued under the Federal Employers’ Liability Act (FELA), alleging workplace exposure to diesel combustion fumes, silica dust, and asbestos caused James’s cancer.
- Plaintiff retained two experts: Dr. Neil Zimmerman (opined on exposures) and Dr. Ernest Chiodo (opined on causation).
- District court excluded Dr. Chiodo’s testimony after finding he misread Zimmerman’s report and assumed above-background exposures to asbestos and diesel fumes that Zimmerman had not established.
- Dr. Chiodo used a differential etiology to assign specific causation but relied on speculative factual assumptions about exposure levels; the court found this made his methodology unreliable under Daubert and Rule 702.
- Because causation could not be established without Dr. Chiodo, the district court granted summary judgment for BNSF; the Eighth Circuit affirmed.
Issues
| Issue | Plaintiff's Argument | Defendant's Argument | Held |
|---|---|---|---|
| Admissibility of Dr. Chiodo’s causation opinion under Daubert/Rule 702 | Chiodo’s differential etiology reliably links James’s work exposures to his lung cancer, relying on Zimmerman’s exposure findings | Chiodo’s opinion rests on incorrect/factually unsupported assumptions about above-background exposures and misreads Zimmerman, rendering his methodology unreliable | Excluded: Chiodo misinterpreted Zimmerman, assumed exposures not established, and applied differential etiology on an insufficient factual basis, making the opinion speculative and inadmissible |
| Whether factual gaps in an expert’s foundation go to admissibility or credibility | Lancaster: Factual disputes should affect weight, not admissibility, given FELA’s relaxed causation standard | BNSF: When an expert’s opinion is speculative or unsupported by sufficient facts it must be excluded under Daubert/Rule 702 | The court held that where an expert’s opinion is speculative and fundamentally unsupported by facts (no evidence of exposure levels), exclusion is proper rather than leaving it to the jury |
| Whether summary judgment was appropriate after exclusion of plaintiff’s causation expert | Lancaster: Even under FELA’s low causation threshold, plaintiff can’t meet causation without admissible expert opinion | BNSF: Without admissible causation expert, Lancaster cannot meet FELA’s causation requirement | Affirmed: Without Chiodo’s admissible testimony, Lancaster cannot prove specific causation and summary judgment for BNSF was proper |
Key Cases Cited
- Daubert v. Merrell Dow Pharms., Inc., 509 U.S. 579 (1993) (gatekeeping duty to assess scientific validity and fit under Rule 702)
- Trost v. Trek Bicycle Corp., 162 F.3d 1004 (8th Cir. 1998) (abuse-of-discretion review for exclusion of expert testimony)
- Brooks v. Union Pac. R.R. Co., 620 F.3d 896 (8th Cir. 2010) (FELA’s relaxed causation standard still often requires expert testimony)
- Concord Boat Corp. v. Brunswick Corp., 207 F.3d 1039 (8th Cir. 2000) (expert must tie opinion to facts of the case to aid the jury)
- In re Wholesale Grocery Prods. Antitrust Litig., 946 F.3d 995 (8th Cir. 2019) (any analytic step that renders analysis unreliable requires exclusion)
- Bland v. Verizon Wireless (VAW) L.L.C., 538 F.3d 893 (8th Cir. 2008) (expert exclusion where degree of plaintiff’s exposure was unknown created too great an analytical gap)
- Wright v. Willamette Indus., Inc., 91 F.3d 1105 (8th Cir. 1996) (plaintiff must at minimum show exposure to levels known to cause claimed harm)
- Rogers v. Mo. Pac. R.R. Co., 352 U.S. 500 (1957) (under FELA, employer’s negligence need only play any part in causing the injury)