Updated Elon Musk's legal grudge against Sam Altman, OpenAI, and Microsoft could soon be over – again – if a California judge responds favorably to the latest filings in the case.

Both [1]OpenAI [PDF] and [2]Microsoft [PDF] filed motions to dismiss Musk's lawsuit last week, arguing that his second attempt to sue the company, [3]filed in August in California federal court after he [4]inexplicably withdrew a nearly identical case in California Superior Court in June, wasn't worth the fees to file it.

"Musk asserted claims, withdrew them, then reasserted them in a new forum, dressed up in new theories, advanced by new lawyers: he sued in state court, then in federal court; he disclaimed a competitive motive, then named his own company as an antitrust plaintiff," OpenAI explained in its motion. "The complaint lurches from theory to theory, distorts its own exhibits, and trades from start to finish on fact-free and often ad hominem conclusions."

[5]

"Musk's pleading is a grudge in search of a lawsuit," OpenAI's lawyers added. "And for all its 105 pages, it fails at its one job: to plead facts that state a claim."

[6]

[7]

The kerfuffle started in March 2024 when [8]Musk sued the super-lab for allegedly breaching its contracts, engaging in unfair business practices, and failing in its fiduciary duties by intermingling itself with Microsoft and creating a for-profit wing.

OpenAI responded by going public with a bundle of emails between OpenAI and Musk going back to 2015 when the [9]DOGE daddy teamed up with Altman, Greg Brockman, and others to form the organization.

[10]

According to OpenAI's presentation of the emails, Musk wanted control of OpenAI. When he didn't get his way, he [11]split from the outfit in 2018. Musk dropped the lawsuit he brought against OpenAI in early 2024 a few months later, though without explaining why.

Fast-forward to today, OpenAI is claiming that both Musk's first and second lawsuits, and an [12]amended complaint filed in November that adds Microsoft to the mix, are baseless attempts to make his own AI firm, xAI, more competitive.

"Boiled all the way down, the complaint asks the Court to intervene in Plaintiffs' favor to improve their position in an intensely competitive industry," OpenAI's lawyers argued. "In 2023, Musk launched a competing AI business – xAI. He has been suing OpenAI ever since, to undermine a successful competitor and advance his own commercial interests."

[13]

Microsoft argued much the same, describing Musk's 26-count lawsuit against it, OpenAI, and multiple named individuals as a "scattershot" attempt "to slow Microsoft and OpenAI down" that fails to land on a single count.

[14]Musk wants to ban Apple at his companies for cosying up to OpenAI

[15]HPE may have bagged $1B order from Elon Musk's X for AI servers

[16]Musk torches $500B Stargate AI plan, Altman strikes back

[17]xAI picked Ethernet over InfiniBand for its H100 Colossus training cluster

"The [amended complaint] is devoid of factual specificity and substantiation, repeatedly relying on unsupported 'information and belief,'" Microsoft's legal team said. "All claims against the Microsoft Defendants lack the necessary factual or legal support."

Microsoft further argued that it shouldn't be party to the whole mess since the complaint was all about OpenAI's founding, in which it wasn't involved.

The filings from Microsoft and OpenAI come after Musk's legal team asked for a [18]preliminary injunction in the case in December as OpenAI began laying out a case for transforming itself into a public benefit corporation, in essence [19]furthering its push toward life as a for-profit company.

California Northern District Court judge Yvonne Gonzalez Rogers has yet to rule on the injunction request, with a hearing on the matter set for later today.

None of the parties involved in the lawsuit, or their legal representatives, responded to questions for this story. ®

Updated to add at 2045 UTC

Judge Gonzalez Rogers [20]today said Elon Musk’s claims of irreparable harm from OpenAI sliding from a nonprofit lab to a normal for-profit operation are a "stretch."

But she also raised an eyebrow at the close ties between Microsoft and OpenAI, and as such has decided to let this go to trial after all.

"It is plausible that what M Musk is saying is true. We'll find out. He'll sit on the stand," the judge said.

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[1] https://regmedia.co.uk/2025/02/04/openai-musk-dismissal-request.pdf

[2] https://regmedia.co.uk/2025/02/04/microsoft-oai-musk-dismissal-request.pdf

[3] https://www.theregister.com/2024/08/05/musk_new_lawsuit_openai/

[4] https://www.theregister.com/2024/06/12/musk_vs_openai_case_ended/

[5] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/aiml&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2Z6KcDFs9Y8CBTdjUR5jhxAAAAUQ&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0

[6] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/aiml&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Z6KcDFs9Y8CBTdjUR5jhxAAAAUQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[7] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/aiml&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33Z6KcDFs9Y8CBTdjUR5jhxAAAAUQ&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[8] https://www.theregister.com/2024/03/01/elon_musk_sues_openai_gpt4/

[9] https://www.theregister.com/2025/02/03/musk_doge_treasury_usaid/

[10] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/aiml&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44Z6KcDFs9Y8CBTdjUR5jhxAAAAUQ&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0

[11] https://www.theregister.com/2018/02/24/ai_roundup/

[12] https://www.theregister.com/2024/11/15/musk_openai_amended_complaint/

[13] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_software/aiml&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33Z6KcDFs9Y8CBTdjUR5jhxAAAAUQ&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0

[14] https://www.theregister.com/2024/06/11/musk_wants_to_ban_apple/

[15] https://www.theregister.com/2025/01/14/hpe_x_ai/

[16] https://www.theregister.com/2025/01/23/musk_altman_stargate_ai/

[17] https://www.theregister.com/2024/10/29/xai_colossus_networking/

[18] https://www.theregister.com/2024/12/02/musk_openai_injunction/

[19] https://www.theregister.com/2024/12/27/openai_for_profit_push/

[20] https://apnews.com/article/elon-musk-openai-lawsuit-sam-altman-3cd261b2a9b04630ec93582020c59ef7

[21] https://whitepapers.theregister.com/