Joseph and Cindy Hirchak sued W.W. Grainger, Inc. and its subsidiary for selling and failing to warn about an allegedly defective product. They based their claim that Grainger sold the product on the opinion of an expert witness. A federal judge in Des Moines ruled that the expert’s testimony was inadmissible and granted summary judgment to Grainger. The Court of Appeals for the Eighth Circuit affirmed that decision.

Facts of the Case

Grainger distributes industrial equipment, including web slings. A web sling consists of straps or webbing. The webbing is typically made from polyester or a similar synthetic material. Web slings are wrapped around heavy objects and attached to a lifting device (such as a crane). The sling supports the objects as they are being lifted.

Joseph Hirchak was employed by Weiler Inc. Hirchak was working at Weiler’s plant when a web sling broke. The sling had been holding a load of steel tubing. The tubing fell on Hirchak, causing injuries.

While workers’ compensation is generally an exclusive remedy against an employer, an injured employee can bring injury claims against third parties if their negligence contributed to a work injury. Hirchak’s suit against Grainger alleged that Grainger supplied a defective web sling to Weiler and failed to warn Weiler about the defect.

Grainger distributes a variety of slings, including slings made by Juli Sling Company. Juli is a Chinese company. Hirchak alleged that the Grainger sold the defective Juli sling to Weiler. Grainger admitted that Weiler has an account with Grainger but denied that it supplied the defective sling to Grainger.

Grainger relied on its sales records and on the absence of Weiler purchase records evidencing sling purchases from Weiler. Grainger also argued that the Juli slings it distributes have sewn-in tags that the defective sling lacked. According to Grainger, those tags are sewn in by Juli. Grainger therefore contended that the defective sling was not a Juli sling.

Expert Evidence

To prove that Grainger supplied the defective sling, Hirchak relied on an expert opinion. Hirchak’s expert identified similarities between the defective sling and slings manufactured by Juli and distributed by Grainger. The expert based that comparison on two Juli slings that Grainger distributed, including a sling purchased from Grainger for the purpose of comparison and one furnished by Weiler. How Weiler determined that the sling was acquired from Grainger was unclear to the appellate court.

Grainger challenged the expert report. Grainger argued that virtually all web slings distributed in the United States share the similarities that the expert identified, regardless of their manufacturer. Grainger also argued that the expert failed to establish that it distributed the defective sling.

District Court Opinion

The district court decided that the expert’s opinion was not based on sufficient facts. Assuming that the points of comparison were sufficient to identify the defective sling as a Juli sling, that identification did not prove that Grainger distributed the sling. Weiler could have acquired it from any of Grainger’s competitors.

After excluding the expert opinion, the district court asked whether the remaining evidence established that Grainger distributed the defective sling. Finding none, it granted summary judgment in Grainer’s favor.

Appellate Opinion

The Eighth Circuit noted that experts must base opinions on sufficient facts to assist the jury in deciding factual disputes. When are facts “sufficient”? One measure of sufficiency is whether the facts both support the expert’s opinion and allow the expert to exclude other possibilities.

The court recognized that it isn’t necessary to rule out every possible alternative conclusion. It is, however, necessary to consider enough facts to account for obvious alternatives. The failure to rule out obvious alternatives suggests that the expert either failed to consider sufficient facts or failed to explain why the expert’s reasoning makes the expert’s conclusion more sound than alternative conclusions.

The court decided that the expert failed to consider sufficient facts to rule out the conclusion that a different distributor supplied the defective sling to Weiler. The expert’s focus was on facts tending to show that Juli manufactured the sling. The expert considered only a few facts to prove that Weiler obtained the sling from Grainger.

The expert compared the defective sling to two Juli-manufactured slings that came from Grainger. That comparison supported a conclusion that Grainger sells slings that are similar to the defective sling. Since other distributors also sell Juli-manufactured slings, the facts upon which the expert relied were not sufficient to rule out the alternative conclusion that a different distributor supplied the sling to Weiler.

Hirchak argued that, since Weiler had a Grainger-distributed Juli sling in its plant, it is reasonable to infer that Weiler acquired the defective sling from Grainger. Oddly, the court of appeals held that the expert could not draw that inference because only the jury could do so. Yet by granting summary judgment, the court deprived the jury of the opportunity to draw the inference.

A better analysis might focus on whether the inference is sufficiently reasonable that it would support a jury verdict in Hirchak’s favor. The fact that Weiler had one Juli-sling that was distributed by Grainger does not imply that all of its other slings came from Grainger.

While an expert may well have been able to identify the manufacturer of the defective sling, identifying its distributor was probably beyond the realm of expert testimony. Purchases and sales are typically proved by purchase records or the testimony of sellers or buyers. In the absence of that evidence, Hirchak had little hope of proving his case through expert testimony.