The US Court of Appeals for the Federal Circuit concluded that a district court did not abuse its discretion in striking expert testimony where the testimony did not rely on an agreed and court-adopted claim construction. Treehouse Avatar LLC v. Valve Corp., Case No. 22-1171 (Fed. Cir. Nov. 30, 2022) (Lourie, Reyna, Stoll, JJ.)

Treehouse owns a patent that describes a “method of collecting data from an information network in response to user choices of a plurality of users navigating character-enabled network sites on the network.” Valve owns two video games. To play the games, a user downloads the software onto a computer. The software contains data, images, sounds, text and characters. Treehouse sued Valve for patent infringement based on the operation of the accused video games. During the district court proceeding, both parties adopted the interpretation of the term “character enabled (CE) network sites” (CE limitation) that the Patent Trial & Appeal Board reached in a previous inter partes review. Despite the agreed-upon and court-adopted construction for the CE limitation, Treehouse’s infringement expert submitted a report that applied plain and ordinary meaning.

Valve filed a motion to strike portions of the expert’s testimony that relied on the plain and ordinary meaning of the term. Valve also filed a motion for summary judgment of noninfringement while this motion to strike was pending. Treehouse’s opposition appeared to concede that Valve was entitled to summary judgment if Valve’s motion to strike was granted, stating that “assuming that [the expert’s] testimony is not stricken, this portion of Valve’s motion should be denied.” The district court struck every paragraph of the expert’s report that Valve requested and granted Valve summary judgment of noninfringement. Treehouse appealed.

The Federal Circuit found that the district court did not abuse its discretion in striking portions of Treehouse’s expert report that did not address the claim construction of the CE limitation agreed upon by the parties and the district court. Treehouse argued that an expert report that does not recite an agreed claim construction remains admissible as long as the opinions expressed in the report are not inconsistent with that construction. The Court rejected Treehouse’s argument, explaining that “the grant of a motion to strike expert testimony is not improper when such testimony is based on a claim construction that is materially different from the construction adopted by the parties and the court.” The Court further explained that when a trial court has adopted a construction that the parties requested and agreed upon, any expert theory that does not rely upon that agreed-upon construction is suspect. The Court thus concluded that the district court did not abuse its discretion in striking the portions of the expert’s report that applied a “plain and ordinary meaning” of the CE limitation instead of the parties’ agreed-upon construction. In the absence of any admissible expert testimony by Treehouse regarding infringement of the CE limitation, the Court found that the district court properly granted summary judgment of noninfringement.