Elon Musk on Thursday sparred with an attorney for OpenAI during his third day of testimony in the contentious trial over the company’s pivot from nonprofit status to a for-profit venture valued at hundreds of billions of dollars.

Elon Musk, the Tesla CEO, world’s richest man and OpenAI’s cofounder, took the stand Tuesday 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.

OpenAI says its board of directors has unanimously rejected a $97.4 billion takeover bid by Elon Musk.