District Court Bifurcates Trial to Decide PGR Estoppel Issues Prior to Jury Trial

October 31, 2025

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The District Court for the Northern District of California recently granted a defendant’s motion to bifurcate, ordering that issues related to PGR estoppel should be decided in a bench trial, while the remaining issues in the case should proceed to a jury trial.

Plaintiffs filed suit alleging that defendant infringed their patent directed to fire wall hanger technology. Following discovery, the court partially granted plaintiffs’ motion for summary judgment, holding that defendant was estopped from asserting one of the three prior art references at issue in the proceedings, but that there were “questions of fact concerning whether [defendant] is estopped from asserting” the other two references. Defendant filed a motion to bifurcate the trial into two phases, proposing that the court conduct a bench trial on the estoppel issue, prior to a jury trial on the issues of infringement and invalidity. Plaintiffs opposed the motion. Following briefing, the court granted defendant’s motion, ordering that the trial should be bifurcated, with the issues on PGR estoppel to be decided by the court in a bench trial.

First, the Court noted that district courts routinely decide the application of PGR and IPR estoppel as a matter of law, and stated that “it is appropriate for the Court to resolve the factual disputes regarding PGR [e]stoppel in a bench trial prior to a jury trial on the legal issues.” The Court then turned to the question of whether bifurcation was appropriate here. To decide whether to bifurcate trial, courts consider several factors, including separability of the issues, simplification of discovery and conservation of resources, prejudice to the parties, and juror confusion. The court determined that bifurcation was warranted here. First, a bench trial on PGR estoppel in this case “would not violate the Seventh Amendment because . . . PGR Estoppel is not a common issue with either infringement or invalidity,” involving different witnesses, law, and facts. Second, bifurcation would promote efficiency and aid judicial economy because the Court was already “well-versed in the facts, expert opinions, and law . . . based on the PGR [e]stoppel briefing.” Additionally, a determination on the PGR [e]stoppel issue could also “obviate the need to adjudicate” aspects of defendant’s invalidity counterclaim.  Third, any delay caused by bifurcation was small compared to the length of the litigation and was outweighed by the risk of prejudice to defendant from a single jury trial where defendant wasted time and resources arguing invalidity theories that were later mooted. Finally, bifurcation would reduce juror confusion because bifurcation would remove several witnesses and complicated testimony from the jurors’ consideration, allowing them to focus on the issues of infringement and invalidity.

Practice Tip: When involved in parallel proceedings before a district court and the PTAB, parties should consider whether any factual disputes related to PGR or IPR estoppel are better resolved by the court prior to a jury trial on infringement and/or validity. A court may favor bifurcation where it could simplify the trial, particularly where the court has already considered the issue in other briefing.

Columbia Insurance Co. v. Simpson Strong-Tie Company Inc., No 19-cv-04683-TSH (N.D. Cal. Aug 21, 2025)

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