Satya Nadella took the witness stand on Monday in Musk v. Altman, the third week of the trial that will decide whether OpenAI can continue operating as a public benefit corporation. Elon Musk is seeking up to $150 billion in damages and the removal of Sam Altman and Greg Brockman from the company he helped cofound in 2015. The Microsoft CEO's appearance follows testimony from Musk himself, his family-office head Jared Birchall, OpenAI cofounder Brockman, and former OpenAI board member Shivon Zilis.
Before Nadella took the stand, jurors watched a video deposition from Michael Wetter, Microsoft's VP of corporate development, who put hard numbers on the Microsoft-OpenAI relationship. Microsoft has recognized $9.5B of total revenue from OpenAI life-to-date as of September 8, 2025, against $13B in committed investment and Azure compute. The figures land in court as Musk argues OpenAI abandoned its nonprofit mission in pursuit of profit.
OpenAI's lead counsel William Savitt has framed Musk's suit as competitive maneuvering. The company said in a statement that "this lawsuit has always been a baseless and jealous bid to derail a competitor," pointing to Musk's xAI and its Grok chatbot, a direct ChatGPT rival. Musk's lead counsel Steven Molo has built the plaintiff's case around the claim that Altman and Brockman induced Musk to fund OpenAI under false pretenses about its nonprofit structure.
Key facts
- 01Microsoft CEO Satya Nadella took the stand as the third week of Musk v. Altman opened, with Ilya Sutskever lined up next.
- 02A Microsoft VP testified the company has booked $9.5B of total revenue from OpenAI life-to-date as of 9/8/2025.
- 03Musk is seeking up to $150B in damages plus the removal of Sam Altman and Greg Brockman from OpenAI.
- 04Judge Yvonne Gonzalez Rogers told Musk's team 'we're in mud' after disputes over the scope of the 2025 OpenAI recapitalization.
- 05Musk expert witness David Schizer of Columbia Law School is being paid $1,500 per hour to testify on nonprofit governance.
Judge Yvonne Gonzalez Rogers has grown visibly impatient with the scope of Musk's theory. On Monday morning she pushed back on a dispute over evidence tied to OpenAI's 2025 recapitalization, which removed the company's profit cap. "I can't get my head around why Mr. Molo told me this was not a focus of the trial," she said. "That's what my ruling is based on." Moments later she added: "We're in mud."
“Microsoft has recognized $9.5B of total revenue from OpenAI life-to-date as of September 8, 2025, against a $13B investment package of cash and Azure compute.”— Jaeden Schafer
Last week's testimony from Mira Murati, OpenAI's former CTO, gave the public its first detailed look inside the board's November 2023 decision to remove Altman. The board's original statement said Altman was "not consistently candid in his communications with the board" — testimony and exhibits in Musk v. Altman have since tied that phrase to specific incidents involving safety processes, Altman's stake in OpenAI's startup fund, and product release decisions.
Former board member Tasha McCauley reinforced that framing in her own video deposition. "Because of this pattern of lying, people in the company were copying that behavior, and there was a culture of lying and a culture of deceit," McCauley testified. Musk's team has used the November 2023 episode — which ended with Altman reinstated after hundreds of OpenAI employees posted "OpenAI is nothing without its people" — to argue Altman cannot be trusted to steer a public benefit corporation.
Court documents released during the trial have also exposed the origins of the Microsoft-OpenAI alliance. After OpenAI's Dota 2 bot beat a professional player in summer 2017, Altman pitched Nadella on a much larger compute partnership — "probably something like $300 million at Azure list prices," Altman wrote. Internal Microsoft communications show executives worried OpenAI would "storm off to Amazon" and "shit-talk" Azure if the deal didn't close, a dynamic that shaped the eventual $13B commitment.
Musk's expert witnesses have drawn mixed reviews inside the courtroom. David Schizer, a Columbia Law School professor of nonprofit law and taxation, is being compensated $1,500 per hour by Musk's team. Under cross-examination, OpenAI's lawyers pressed Schizer on Columbia itself — which generates roughly $2 billion from hospital operations, more than $1 billion in tuition, holds a $16 billion endowment, and pulls in $2.2 billion in philanthropy — to argue that nonprofit institutions routinely operate complex commercial activities without abandoning their missions.
Ilya Sutskever, OpenAI's cofounder and former chief scientist, is scheduled to testify after Nadella. Sutskever was central to the November 2023 board decision and later founded Safe Superintelligence Inc., giving his testimony unusual weight on both the events at issue and the broader question of OpenAI's safety culture. Musk's team will likely use Sutskever to argue the mission shift is real; OpenAI's team will likely use him to argue the company's structure still serves it.
The plaintiff's case has not been clean. Earlier coverage of the trial noted Musk appeared "more petty than prepared" during his own testimony, and Brockman and Zilis both pushed back on the framing that Musk was a passive donor — testifying he pressed for a for-profit OpenAI early on and attempted to recruit Altman to a Musk-controlled entity. Judge Gonzalez Rogers's frustration suggests the legal theory tying OpenAI's recapitalization to a breach of Musk's original donation has not landed cleanly.
The dollar figures around the case are now larger than the case itself. OpenAI is in talks at valuations measured in the high hundreds of billions, Microsoft has booked $9.5B in OpenAI revenue, and the company's compute footprint runs through every hyperscaler's capex plan. A $150B damages award is unlikely on the current record, but a ruling that constrains OpenAI's corporate structure would ripple through every deal the company has signed since 2019.
For the broader AI market, the trial's real product is disclosure. Public testimony has now put hard numbers on the Microsoft-OpenAI relationship that the two companies have spent five years declining to itemize, exposed the internal mechanics of the November 2023 board crisis, and surfaced the email trail behind the original Azure deal. Whatever Judge Gonzalez Rogers decides, the competitive intelligence already entered into the record is the kind of thing rival labs, regulators, and the next round of OpenAI investors will be reading carefully.
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