A lawyer for Elon Musk hammered at the credibility of OpenAI CEO Sam Altman on Thursday, near the end of a trial over whether to hold the ChatGPT maker and its leaders responsible for allegedly transforming the nonprofit into a vehicle to enrich themselves.

OpenAI’s lawyers fought back, claiming the world’s richest person waited too long to claim OpenAI breached its founding agreement to build safe artificial intelligence to benefit humanity, and couldn’t claim he was essential to its success.

“Mr. Musk may have the Midas touch in some areas, but not in AI,” said William Savitt, a lawyer for OpenAI. “To succeed in AI, as it turns out, all Mr.…