Monday was the kind of day that makes you realize this trial isn't just a legal proceeding. It's a public autopsy of the most consequential company in AI, performed live in an Oakland federal courtroom while the whole industry watches.

Three witnesses took the stand on Day 10 of Musk v. Altman: Microsoft CEO Satya Nadella, former OpenAI chief scientist Ilya Sutskever, and current OpenAI board chairman Bret Taylor. Between them, they painted a picture of a company that stumbled into a trillion-dollar valuation while its founders couldn't agree on what it was supposed to be.

Nadella: 'Amateur City'

Nadella was called by Musk's legal team, but he may have done more damage to their case than anyone expected. The Microsoft CEO testified that Musk personally thanked him for Azure cloud support in 2017 and never once complained as Microsoft's financial relationship with OpenAI deepened into a $13 billion partnership.

But the real fireworks came when Nadella described the November 2023 board coup that briefly removed Altman as CEO. His verdict? "Amateur city." He testified that he never received clarity on why Altman was fired, and that he was pulled out of a meeting and informed of the decision after the fact.

The most revealing moment: a 2022 email where Nadella wrote "Microsoft will lose 4 bil next year!!!" on the OpenAI partnership, demanding the deal be restructured so Microsoft would also get AI "know-how" from the startup. "If we are going to spend this kind of money and not have control of destiny, it makes no sense," Nadella wrote. That's the CEO of a $3 trillion company admitting, in writing, that OpenAI had leverage over Microsoft. Not the other way around.

Sutskever: The $7 Billion Witness

Ilya Sutskever arrived without a suit jacket (the first male witness to do so) and testified for about an hour. He disclosed that his stake in OpenAI's for-profit arm is currently worth around $7 billion, making him one of the largest known individual shareholders. For context, Brockman revealed earlier in the trial that his shares are worth about $30 billion.

Sutskever's testimony cut both ways. He bolstered Musk's case by standing behind his decision to fire Altman in 2023, saying an "environment where executives don't have the correct information" isn't "conducive to reach any grand goal." But he also helped OpenAI's defense by confirming that Musk never negotiated special promises when funding the nonprofit. The for-profit transition, Sutskever said, was the consensus path forward because "if there's no funding, there is no big computer."

The most human moment: Sutskever, who left OpenAI in 2024 to start a competing lab, looked visibly dejected on the stand. "I felt a great deal of ownership of OpenAI," he said. "I felt like I put my life into it, and I simply cared for it, and I didn't want it to be destroyed."

Taylor Opens the Defense

After Sutskever stepped down, Musk's side rested its case. OpenAI's legal team immediately called board chairman Bret Taylor, who gave Altman a glowing review. Taylor told jurors that Altman had recused himself from a 2024 content deal with Reddit (where Altman holds a stake), and that Altman had only gotten involved to "bring down the temperature" when negotiations veered toward a lawsuit.

"He's been forthright with me and the other board members and grown OpenAI in ways that have exceeded my expectations," Taylor testified. He didn't finish his testimony before the court adjourned and will return Tuesday morning.

What Happens Next

Tuesday is the main event. Taylor finishes his testimony, and then Sam Altman takes the stand. This will be the first time Altman publicly tells his side of the story under oath, facing direct questioning from Musk's attorneys. Closing arguments are expected Thursday, with jury deliberations possibly beginning the same day.

The scorecard so far: Musk's team has established that multiple insiders questioned Altman's honesty and that the for-profit transition fundamentally changed what OpenAI was. But OpenAI's defense has a strong counter: Musk knew about the Microsoft partnership, thanked Nadella for it, and never objected as the money flowed in. The question for the jury isn't whether OpenAI changed. It's whether Musk was deceived about the change, or whether he just didn't like how it turned out.

I've covered this trial from Day 1. Tomorrow might be the most important day of testimony we'll see. Altman's performance on that stand could determine whether Musk walks away with damages or walks away with nothing.