Microsoft CEO Satya Nadella will testify this week in the landmark lawsuit where Elon Musk accuses OpenAI of abandoning its nonprofit mission to advance artificial intelligence for humanity's benefit.

It is expected that Nadella will discuss the emails that showed how the $13 billion investment by Microsoft changed OpenAI from a research laboratory to a profit-making venture.

Musk wants OpenAI to become a non-profit organisation again, and he has even taken legal action against the company, demanding about $38 million from his initial investment and $134 billion for the damage caused.

The attorneys of Musk have claimed that Microsoft deliberately assisted OpenAI in turning it into a commercial organisation. It was revealed recently through emails in January 2018 that Nadella was weighing down on providing Azure access to OpenAI at a reduced price.

At the time, Nadella expressed scepticism about the company's research trajectory, writing: "Overall I can't tell what research they are doing and how, if shared with us, it could help us get ahead."

Contrary to initial doubts, Microsoft invested $1 billion worth of funding back in 2019, raising its total investment to $13 billion by 2023.

Before Nadella’s testimony, OpenAI’s former chief technology officer Mira Murati testified that CEO Sam Altman caused distrust and confusion among executives. "My concern was about Sam saying one thing to one person and completely the opposite to another person," Murati told the court.

According to her, A.I. Altman engaged in deception with executives and created "chaos" internally. However, despite these statements, she testified that she supported Altman's return as CEO, even after his temporary dismissal in 2023, fearing “OpenAI was at catastrophic risk of falling apart.” The contradiction indicates that there was much happening behind closed doors.

Elon Musk publicly commented on Murati’s testimony by calling her “cool” with a heart emoji.