Musk filed the lawsuit last week in San Francisco against the company, Chief Executive Officer Sam Altman and President Greg Brockman, alleging it had strayed from its mission to build responsible AI. In the post, OpenAI said that Musk was lashing out after trying and failing to make the company part of Tesla Inc. 

“We’re sad that it’s come to this with someone whom we’ve deeply admired” OpenAI wrote, “someone who inspired us to aim higher, then told us we would fail, started a competitor, and then sued us when we started making meaningful progress towards OpenAI’s mission without him.”

The billionaire Tesla CEO, a co-founder of OpenAI who is no longer involved in the company, alleges in his suit that the startup’s close relationship with Microsoft Corp. has undermined its original mission of creating open-source technology free from undue corporate influence.

“To this day, OpenAI Inc.’s website continues to profess that its charter is to ensure that AGI ‘benefits all of humanity,’” the lawsuit said. “In reality, however, OpenAI Inc. has been transformed into a closed-source de facto subsidiary of the largest technology company in the world: Microsoft.”

AGI, or artificial general intelligence, refers to a type of AI that doesn’t yet exist but that could, theoretically, perform a variety of tasks better than humans.

Musk is suing for breach of contract, breach of fiduciary duty and claims of unfair business practices, among other grievances. He is bringing the suit in the capacity of a donor to the nonprofit parent organization as recently as 2019, and is seeking to force San Francisco-based OpenAI to stop benefitting Microsoft and Altman personally.

OpenAI did not comment publicly on Musk’s suit when it was originally filed on Feb. 29. But in an internal memo reviewed by Bloomberg, the company said it “categorically disagrees” with the lawsuit.