Last week, the U.S. Court of Appeals for the Federal Circuit issued an opinion in BISSELL, Inc. v. International Trade Commission, Nos. 24-1509, -1709 (May 11, 2026), affirming the ITC’s Final Determination that an expert may rely on source code produced in discovery to support a domestic industry finding even when that source code is not formally introduced as an exhibit at trial.
BISSELL complained that Tineco’s wet-dry surface cleaning devices infringed the claims of two patents. The Commission found that Tineco's original accused products infringed and entered a limited exclusion order as to those products, but found that Tineco's redesigned products did not infringe the claims. Both parties appealed.
Tineco challenged, inter alia, the Commission’s finding that BISSELL’s domestic industry products practiced the “disabled battery” limitation. Specifically, Tineco argued that the ALJ erred by relying on BISSELL’s expert, Dr. Sorensen, because his testimony was based on source code that was produced during discovery but never introduced as a trial exhibit.
The Federal Circuit disagreed, holding that expert testimony may be more extensive than the exhibits formally introduced into evidence. The Court pointed to Federal Rule of Evidence 703, which permits an expert to base an opinion on facts or data not themselves admissible, provided experts in the field would reasonably rely on such information. The Court emphasized that there was no dispute the source code was produced in discovery, that Dr. Sorensen relied on it, that experts in the field would reasonably rely on source code to understand product operation, and that Tineco never offered contrary expert opinions. The Court further noted that Tineco had not even asserted in its prehearing brief that BISSELL's products failed to practice the limitation and did not cross-examine Dr. Sorensen on the issue.
The Court held that substantial evidence supported the Commission’s finding. This decision provides important guidance for Section 337 complainants establishing a technical domestic industry. Practitioners should note that unrebutted expert testimony relying on discovery materials—even those not formally admitted as exhibits—can constitute substantial evidence supporting a domestic industry finding, particularly where the opposing party fails to challenge the testimony at the hearing stage.
The Federal Circuit also affirmed the Commission’s no-infringement finding as to Tineco’s redesigned products, concluding that BISSELL improperly challenged factual findings as legal conclusions without contesting substantial evidence.
