The Grudge Behind the GPT: Billionaires’ Bitter OpenAI Battle Boils Over

17 May 2026 | Oakland, California

OAKLAND, California – "When the father of your babies starts a competitive effort and will recruit out of OpenAI, there's nothing to be done."

That text message, sent by Shivon Zilis – the mother of four of Elon Musk's children – to a friend, captures the strange, tangled, deeply personal reality at the heart of the most consequential tech trial in years.

After three weeks of cringey courtroom drama, a nine-person jury is set to decide whether Elon Musk's allegations that Sam Altman "stole a charity" are legitimate. Deliberations begin Monday. Whatever the outcome, the case has been an illuminating, at times exhausting, look behind the scenes at the history of OpenAI and how some of the most powerful figures in the tech industry operate.

Attorneys for both sides have introduced reams of private text messages, emails and even diary entries. A who's who of Silicon Valley testified, including Microsoft CEO Satya Nadella and Zilis herself. Both Altman and Musk took the stand for hours, facing combative cross-examinations that painted them each as untrustworthy.

"It's Not OK to Steal a Charity": Musk's Opening Salvo

The core of Musk's case revolves around allegations that Altman, OpenAI and its president, Greg Brockman, broke a founding agreement of the AI firm, established as a non-profit in 2015, when they later restructured it into a for-profit entity. Musk claims that he was swindled by Altman, who lured Musk in as a co-founder and took his financial backing, then twisted the company for personal gains.

"They're going to make this lawsuit very complicated, but it's actually quite simple," Musk said during his testimony. "Which is: it's not OK to steal a charity. That's my view."

OpenAI has denied all of Musk's allegations, arguing that not only was he aware of plans to create a for-profit entity but that he made a failed bid to take total control of the company, departed it in a huff in 2018, and founded a competitor, xAI. OpenAI has cast Musk as a sore loser in the AI race who is seeking revenge through the suit.

Musk is seeking the removal of Altman and Brockman, the undoing of OpenAI's for-profit restructuring and the redistribution of $134 billion from its for-profit entity to its non-profit organization. If the jury finds OpenAI is liable, the verdict could present sizable difficulties for the company, which is seeking to go public later this year at a valuation of $1 trillion.

"Your Questions Are Designed to Trick Me": Musk's Combative Testimony

The first marquee witness was Musk himself, who testified for three consecutive days. His testimony began with friendly questioning from his lead attorney, allowing Musk to recap his career and present his story of OpenAI's beginnings. In Musk's retelling, he was the primary reason the company ever got off the ground. He argued that his benevolent hopes for OpenAI were dashed by a conniving Altman, who seized control and abandoned its charitable mission in pursuit of profit.

The testimony took a turn as soon as Musk's cross-examination began. OpenAI's lead attorney, William Savitt, prodded him with rapid-fire questions about what he knew about the AI firm's for-profit plans and when he knew them. The judge cautioned Musk not to give meandering answers. At points, he became testy, once likening Savitt's questions to being asked "have you stopped beating your wife" – eliciting a rebuke from the bench.

"Your questions are not simple. They are designed to trick me, essentially," Musk said to Savitt.

Musk wasn't present for remaining parts of the trial and, despite the judge's order that he remain ready to be recalled, he joined Donald Trump this week on a diplomatic trip to China.

"Mr Musk isn't here today. My clients are," OpenAI's lawyer said during his closing arguments. "Mr Musk came to this court for exactly one witness: Elon Musk. Now he's in parts unknown." Musk's lawyer sheepishly apologized for his client's absence.

"A Consistent Pattern of Lying": The Case Against Altman

After Musk's testimony, his lawyers presented several video depositions and called a series of witnesses to show that Altman was not trustworthy. Several of OpenAI's former top executives took the stand, often rehashing a five-day period in 2023 when Altman was fired by the OpenAI board before being reinstated amid a power struggle.

Former chief technical officer Mira Murati described Altman as often "saying one thing to one person and completely the opposite to another person." Former board member Natasha McCauley accused Altman of creating "repeated crisis events" through his leadership.

OpenAI co-founder and former chief scientist Ilya Sutskever was questioned about statements in his deposition regarding Altman's dishonesty.

"You told the board that Altman 'exhibits a consistent pattern of lying, undermining his execs and pitting his execs against one another'," Musk's lawyer asked.

"Yes," Sutskever responded.

Sutskever, McCauley and Murati were all involved in the 2023 attempt to push out Altman and have since left the company.

"Mr Musk Tried to Kill It": Altman's Rebuttal

When Altman took the stand in the final week, he presented his own version of OpenAI's history. Altman argued that Musk was a difficult, erratic co-founder who demoralized staff with an aggressive management style and sought power for himself. At one point, Altman alleged, Musk wanted "total control" over the company and once suggested that power could be passed down to his children when he died.

Altman also took aim at Musk's mantra that his rival stole a charity. "This whole 'you can't steal a charity'. I agree you can't steal it. Mr Musk did try to kill it," Altman said.

During cross-examination, Musk's lawyer pressed Altman on whether he was trustworthy.

"You've repeatedly been called deceptive and a liar by people with whom you've done business, right?" the lawyer asked.

"I have heard people say that," Altman responded.

"Amateur City": Nadella's Dig at OpenAI's Board

Microsoft CEO Satya Nadella, called because Microsoft is OpenAI's primary business partner and is also accused in the suit of aiding and abetting OpenAI's breach of trust, took the stand on Monday. He discussed his own role in OpenAI's development and took a dig at the board members who tried to oust Altman in 2023 – saying they couldn't communicate their rationale and threw the company into chaos.

"It was sort of amateur city, as far as I'm concerned," Nadella testified. "I was very worried that the employees were going to leave en masse."

"It's Very Painful": Brockman's Personal Diary Exposed

Brockman faced scrutiny over a personal diary he kept during OpenAI's founding years, which contained entries like "financially, what will take me to $1bn?" Musk's lawyers presented the diary as proof of callous ambition and intent to deceive their client, while OpenAI framed it as a cherry-picked, stream-of-consciousness document that proved nothing.

Either way, Brockman did not seem happy about it becoming public.

"It's very painful," Brockman said. "It's very deeply personal writings that weren't meant for the world to see, but there's nothing in there that I'm ashamed of."

"When the Father of Your Babies Competes": Zilis's Text Exchange

The trial became even more personal when Zilis – the mother of four of Musk's children and an executive at Neuralink – took the stand. OpenAI's lawyers accused her of acting as an insider source for Musk while she was on OpenAI's board, funneling him information while hiding her romantic involvement with the billionaire. Zilis denied ever acting as a spy for Musk.

At one point, lawyers brought up a text exchange between her and a friend after it became public that Musk was starting his own AI company in 2023 and she left OpenAI's board.

"E's effort has become well known," Zilis texted.

"Fuck," the friend responded. "You ok."

"When the father of your babies starts a competitive effort and will recruit out of OpenAI there's nothing to be done," Zilis replied.

The message – raw, honest, and deeply human – captured the impossible position Zilis found herself in: loyal to Musk, committed to OpenAI's mission, and caught in the middle of a billion-dollar legal war.

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