Elon Musk spent three days on the witness stand to testify in his high-stakes lawsuit against OpenAI. JOSH EDELSON / AFP via Getty Images The author was in the Oakland courthouse when Elon Musk testified in his case against OpenAI. Musk's testimony started with his life story and ended with a lengthy spar with OpenAI's attorney. The presiding judge runs a tight schedule and is not shy about putting billionaires in their place. The air in Downtown Oakland felt different the morning Elon Musk showed up to testify at the federal court in his high-stakes lawsuit against OpenAI . "What's going on out there?" a cyclist asked as we waited for the traffic light just shy of 7 am on Tuesday, gesturing to the swarm of police vehicles on the block ahead of us. "Is someone in trouble?" "That depends," I said, as I rushed to cover the legal soap opera drama unfolding between the world's richest man and his former AI partner, Sam Altman .…