A combination photo shows CEO of OpenAI Sam Altman (L) on April 28, 2026 and Elon Musk on April 29, 2026 during the trial in Elon Musk's lawsuit over OpenAI for-profit conversion at a federal courthouse in Oakland, California, U.S. Manuel Orbegozo | Reuters OpenAI CEO Sam Altman testified in the Musk v. Altman trial on Tuesday, where he tried to make his central claim clear to the jury: He didn't steal a charity , but Elon Musk abandoned one.  Altman, wearing a blue suit and tie, spoke from the witness stand in federal court in Oakland, California over the course of about four hours.…