Barbara Ortutay Updated April 29, 2026 — 9:14am , first published 5:40am California: Elon Musk, the Tesla CEO, world’s richest man and OpenAI co-founder, took the stand on Tuesday (US time) in a high-stakes trial revolving around a bitter feud between himself and former friends Sam Altman and Greg Brockman that could reshape the future development of artificial intelligence . The bickering billionaires’ appearances at the Oakland federal courthouse foreshadows the start of a legal drama that is expected to brim with intrigue and potentially embarrassing details about the two tech moguls. Musk filed the lawsuit against Altman and Brockman along with Microsoft over its investments in OpenAI, in 2024. Elon Musk arrives at the federal courthouse in Oakland, California.…