OpenAI CEO Sam Altman took the witness stand Tuesday to defend his business record in a trial pitting him against Elon Musk, rebutting testimony that disparaged his leadership at a pivotal time for the ChatGPT maker. Musk, the world’s richest man, is seeking Altman’s second ouster from the company leadership as part of a civil lawsuit accusing him of betraying their shared vision for OpenAI. Altman testified to a number of concerns he had about Musk’s attempts to gain more control over OpenAI, which was aiming to safely build a better-than-human form of AI called artificial general intelligence.