A patent owner waited a year too long before trying to disqualify Latham & Watkins from an infringement case involving Amazon.com, a federal judge ruled Thursday.

U.S. District Judge Jon Tigar of San Francisco ruled that Eolas Technologies Inc. knew Latham was representing Amazon since January 2016 but didn't move to disqualify until early this year. Along the way, Tigar resolved an issue of first impression in legal ethics, applying the law of Texas—where the patent dispute originated—rather than California law.

“When Latham agreed to represent Amazon, this case was pending in the Eastern District of Texas, and Latham would have been correct to expect that Texas ethical codes would apply to any motion to disqualify,” Tigar wrote in Eolas Technologies v. Amazon.com.