( June 22, 2026, 2:16 PM EDT) -- WASHINGTON, D.C. — A Federal Circuit U.S. Court of Appeals panel reversed a Washington federal judge’s finding that video game company Valve Corp. was estopped from asserting invalidity arguments in defense of infringement claims asserted against it regarding a patent describing a video game controller with extra buttons located on the back; the panel held that the judge relied on insufficient evidence and failed to account for hindsight bias....