Satya Nadella, the CEO of Microsoft, took the stand in Elon Musk's trial against Sam Altman and OpenAI. Manuel Orbegozo/Reuters The Musk v. Altman trial began its third week with testimony by Microsoft CEO Satya Nadella. Nadella was called by Musk's lawyers — but he could end up helping OpenAI, Sam Altman, and Microsoft. Closing arguments in the Oakland, California, contest between two tech titans could come Thursday. On Monday, the Musk v. Altman trial entered its final stretch, with Elon Musk's side calling its final witnesses — including Satya Nadella, CEO of Microsoft . The charismatic CEO described the inner workings of the decadelong, multi-billion-dollar partnership between Microsoft and OpenAI. It's a key dynamic in Musk's lawsuit against Sam Altman and OpenAI. According to Musk, Altman joined in "looting" OpenAI by turning a nonprofit meant to benefit humanity into a goliath that made billions through its relationship with the Big Tech company. Nadella's testimony seemed to mostly work against Musk.…