A few months before Elon Musk left OpenAI’s board of directors in February 2018, he tried to recruit Sam Altman to join a “world-class AI lab” within Tesla. Musk went as far as offering the OpenAI CEO a Tesla board seat, according to emails and testimony presented in federal court on Wednesday during the Musk v. Altman trial. The emails were shown to a jury during the cross examination of Shivon Zilis, a former OpenAI adviser and board member who is also the mother of four of Musk’s children.

Musk’s core claim in this lawsuit is that Altman and OpenAI president Greg Brockman effectively stole a nonprofit, using the $38 million Musk invested to create a private company worth more than $800 billion today. On Wednesday, lawyers for Musk showed video depositions of former OpenAI CTO Mira Murati and former OpenAI board member Helen Toner, to raise concerns over Altman’s alleged history of deceit.

OpenAI’s legal team has responded to Musk’s claims by questioning his true motives, arguing that the Tesla CEO has had “sour grapes” ever since he