Friendship breakups are never easy, but few are as messy and expensive as the collapse of Elon Musk and Sam Altman’s once thriving tech bromance.

On Thursday, closing arguments wrapped up in Musk’s lawsuit against OpenAI, leaving a jury to deliberate next week whether Altman and other executives “stole a charity” (as one of Musk’s lawyers put it) by turning much of what was once a nonprofit research lab into a corporate behemoth. (Disclosure: Vox Media is one of several publishers that have signed partnership agreements with OpenAI. Our reporting remains editorially independent.) For three weeks, lawyers on both sides have deployed an increasingly unhinged body of evidence in an attempt to discredit both men and prove they’re untrustworthy and power-hungry.

If the jury rules that Musk was duped into donating roughly $38 million to OpenAI under false pretenses, then Judge Yvonne Gonzalez Rogers will decide on the damages, which could potentially lead to $150 billion in financial restitution and, while unlikely, could also include major changes to OpenAI’s leadership and governance structure. Even if the jury does not rule in Musk’s favor, however, it’s possible that the evidence put forth at trial will be enough to convince state regulators to revisit the agreements that allowed OpenAI to restructure into a for-profit enterprise to begin with.

Lawyers tell me that whoever loses will likely appeal, meaning the catfight might not be over yet. But for now, here are five major revelations from the trial.

Musk’s legal team sought to paint Altman as a deeply untrustworthy person, prone to lying to his co-founders, employees, and board members if it meant advancing his interests.

Multiple former OpenAI employees and board members testified as much in the courtroom. Altman’s “pattern of behavior related to his honesty and candor” led directly to his temporary ouster as CEO in 2023, said Helen Toner, a former board member, in a video deposition. He had a tendency of “saying one thing to one person and completely the opposite to another person,” Mira Murati, OpenAI’s former chief technology officer, testified. In one instance, she said, Altman explicitly lied to her about the safety review required to vet a new AI model.

Some of the more salacious evidence entered into trial came from a personal diary kept by OpenAI president Greg Brockman, who chronicled his “stream of consciousness” as he weighed whether it would be “morally bankrupt” to pivot OpenAI into a for-profit enterprise.

“Can’t see us turning this into a for-profit without a very nasty fight,” he wrote in one 2017 entry. “It’d be wrong to steal the nonprofit from him,” meaning Musk, who co-founded OpenAI and provided most of its start-up funding. “He’s really not an idiot,” Brockman later wrote. “His story will correctly be that we weren’t honest with him in the end.”

Brockman was also candid about his personal ambitions; “It would be nice to be making the billions,” he wrote. He later received a stake in OpenAI now estimated to be worth about $30 billion.

OpenAI built a bot in 2017 that was so advanced, it could beat top professional players at strategic multiplayer battle game Dota 2, a major milestone for the budding lab. “Time to make the next step for OpenAI. This is the triggering event,” Musk emailed Brockman.

Musk gave Brockman and cofounder Ilya Sutskever new Tesla Model 3 cars, presumably to “butter us up,” Brockman testified. The Tesla CEO then summoned them to his self-described “haunted mansion” for discussions of a possible OpenAI for-profit arm, where whiskey was served by Musk’s then-girlfriend Amber Heard.

At one point, Musk became so irate at his guests’ insistence that they share control of OpenAI — rather than cede absolute control to Musk — that “I actually thought he was going to hit me, physically attack me,” Brockman testified. In the following months, Musk repeatedly pitched having Tesla absorb OpenAI, Altman testified. And, in one “particularly hair-raising moment,” he mused that OpenAI should pass on to his children.

Musk ultimately left OpenAI in 2018 to begin building his own competitor. During an all-hands meeting, Musk got into another tense verbal tussle with Josh Achiam, now OpenAI’s chief futurist, over the race to develop artificial general intelligence. “He snapped and called me a jackass,” Achiam testified. For Achiam’s valor, two OpenAI employees — including Dario Amodei, who later departed to form Anthropic — awarded him a small golden statue of a donkey’s rear end, inscribed with the message, “Never stop being a jackass for safety.”

Musk first funded OpenAI because of another friendship breakup, this one with Google cofounder Larry Page, who Musk says mocked him at his own birthday party for preferring humans over computers. Microsoft — which is named in Musk’s lawsuit for aiding and abetting OpenAI’s abandonment of its nonprofit mission — later became OpenAI’s first major corporate investor in 2019, because it, too, wanted to compete with Google as the AI race heated up.

“I don’t want to be IBM,” Microsoft CEO Satya Nadella wrote to executives, referring to that company’s decline in the personal computing race, according to emails revealed at trial. “It was becoming even more core and important that we had real agency at every layer of the stack,” Nadella testified.

That meant ingratiating itself in every corner of OpenAI’s world. Microsoft played a crucial role in bringing Altman back to power after the failed board coup in 2023, which Nadella referred to as “amateur city, as far as I was concerned.” In a text thread revealed at trial, Altman asked Microsoft executives to vet various members of OpenAI’s reconstituted board of directors, who now control both the for-profit company and the original nonprofit.

By this summer, Microsoft will have invested over $100 billion in OpenAI, one of the company’s executives testified. The company was awarded a 27 percent stake in OpenAI last fall.

Microsoft. Musk. Altman. Brockman. Almost everyone who testified at trial pointed fingers at a different boogeyman whose motives were too impure and whose character was too corruptible, to be trusted with control of what all agreed would be an extremely consequential technology. By contrast, their own introspection mostly took a back seat to ambition.

“We don’t want to have a Terminator outcome,” Musk testified, to apparent eyerolls from Judge Gonzalez Rogers, who tried and sometimes failed to steer the trial away from discussions of AI’s existential risks. “If you have someone who is not trustworthy in charge of AI,” Musk said, “I think that’s a very big danger for the whole world.”

Over a decade ago, Musk came together with OpenAI’s cofounders to build a charity equipped to take on a different threat then poised to lead the AI race: Google, which had recently acquired Demis Hassabis’ DeepMind. Now, like Altman and Brockman, who testified that they resisted Musk’s dictatorial attempts to secure absolute control of artificial general intelligence, Musk portrayed himself as someone selfless and transparent enough to be put in charge.

“It is ironic that your client, despite these risks, is creating a company that is in the exact space,” Gonzalez Rogers at one point told Musk’s lawyer, in reference to xAI, which has come under fire this year for facilitating the mass creation of nonconsensual deepfakes. “I suspect there are plenty of people who wouldn’t like to put the future of humanity in Mr. Musk’s hands.”