OpenAI CEO Sam Altman Takes the Stand in Musk Lawsuit as Board Chair Wraps Testimony

OpenAI CEO Sam Altman is set to testify Tuesday in federal court in Oakland, California, in Elon Musk's lawsuit against the artificial intelligence company, following the conclusion of board chairman Bret Taylor's testimony.

Altman's lawyers informed Judge Yvonne Gonzalez Rogers on Monday that he would take the stand after Taylor finished. Taylor returned to the courtroom at 8:30 a.m. PT Tuesday to resume testimony he began the previous afternoon.

Musk sued OpenAI, Altman, and company president Greg Brockman in 2024, alleging the organization abandoned its commitment to operate as a nonprofit and strayed from its charitable mission. Musk, who co-founded OpenAI alongside Altman and Brockman in 2015, claims the approximately $38 million he donated to the company was used for unauthorized commercial purposes.

During the first week of proceedings, Musk took the stand himself and repeatedly accused Altman and Brockman of attempting to enrich themselves and "steal a charity."

Taylor's testimony on Monday covered the role of OpenAI's board and the company's corporate structure, both before and after its recapitalization last year. He described the new structure as more straightforward for employees and investors while maintaining that OpenAI's nonprofit remains in control.

Taylor also noted that certain investors — including SoftBank and Thrive Capital — made their commitments conditional on the transition to the new structure. He further addressed the turbulent period in late 2023 when Altman was briefly removed as CEO.

"I would describe it as dire," Taylor testified. "It felt like the organization might collapse if a resolution was not reached."

Microsoft CEO Satya Nadella also testified on Monday. Microsoft has invested more than $13 billion in OpenAI since 2019, and Musk named the company as a defendant, alleging it aided and abetted OpenAI's purported breach of charitable trust.

Nadella said Musk never raised concerns with him that Microsoft's investments violated any special terms or commitments. Reflecting on the chaos surrounding Altman's ouster and reinstatement, Nadella said his priority had been maintaining continuity for Microsoft.

"It was sort of amateur city, as far as I'm concerned," Nadella testified.

Adding another layer of pressure on Altman ahead of his courtroom appearance, the House Oversight and Government Reform Committee sent him a letter on Friday seeking information about how OpenAI identifies and manages conflicts of interest. Committee Chair Rep. James Comer cited disclosures — surfaced during the litigation — that president Brockman holds stakes in two startups backed by Altman and holds a percentage of Altman's family fund.

Comer also flagged OpenAI's proposed investment in Helion, a nuclear fusion company in which Altman personally holds a stake. "These details further raise concerns to the Committee about potential conflicts of interest arising from your use of OpenAI to potentially bolster the value of other companies and startups which you hold a financial stake in," the letter said.

Comer requested information about OpenAI's audit committee and all relevant policies for directors and officers, with a deadline of May 22.

Altman's testimony is expected to be the most closely watched moment of the trial, which began in late April, with the CEO facing scrutiny both inside the courtroom and on Capitol Hill.

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