The Wisconsin Court of Appeals recently decided one of the first cases analyzing the exclusion of an expert witness under the recently-revised Wis. Stat. § 907.02(1), Wisconsin’s Daubert statute. In Nationwide Agribusiness v. August Winter & Sons, Inc., No. 2014AP488 (Wis. Ct. App. Oct. 2, 2014), Nationwide was trying to recover payments it made to its insured for property damage and business interruption expenses caused by an explosion of a boiler which August Winter had installed and placed into service. Nationwide planned to call a single expert witness, Duane Wolf, to prove causation. In his report, Wolf opined that an August Winter employee failed to sufficiently tighten a screw, which resulted in the accumulation of excessive gas and, ultimately, caused the explosion.
August Winter filed a pretrial motion to exclude Wolf’s testimony arguing, among other things, that Wolf’s deposition showed that his opinion depended on an assumed fact with no basis. Wolf assumed that the screw was too loose at the particular time of the explosion and based that assumption on scratch marks the screw left, without explaining why the scratch marks could not have occurred at another point in time. The circuit court agreed with August Winter that Wolf’s factual assumption lacked support and excluded Wolf’s causation opinion.
On appeal, Nationwide argued that the circuit court failed to engage in a proper analysis under the Wisconsin Daubert Statute, and therefore that the Court of Appeals should not defer to the court’s exercise of discretion in making its determination. Instead, Nationwide argued, the court of appeals should review the matter de novo.
The Court of Appeals explained that the Circuit Court did conduct a proper analysis under the statute, but that even reviewing the matter de novo, the circuit court had correctly excluded Wolf’s testimony. In its de novo review, the Court of Appeals focused on the issue of whether the expert testimony was based upon sufficient facts or data, as required by § 907.02(1). The Court of Appeals agreed that Wolf’s causation opinion was incomplete as it depended on an unsupported factual assumption as argued by August Winter. There was no factual basis for Wolf’s assumption that the screw was in fact too loose at the time of the explosion. His opinion depended on an assumption about when the scratch marks were made, and there was no evidence supporting his assumption that the scratch marks were made at the relevant time rather than a prior time. Thus, the court concluded that Wolf’s testimony was properly excluded as his opinions were not based on sufficient facts and data as required.