Sam Altman appeared to troll Elon Musk by dredging up a years-old Twitter post

• Elon Musk filed a lawsuit against Sam Altman and OpenAI last week.
• Following the news, Altman resurfaced an old Twitter exchange with Musk by replying to the thread.

Sam Altman seemed keen to attract Elon Musk's attention by resurfacing an old conversation with the billionaire.

After Musk filed a lawsuit against him and OpenAI, Altman replied to an exchange from 2019, back when the platform was known as Twitter, between him and the billionaire.

The OpenAI chief wrote "anytime" next to a salute emoji in the conversation thread, in which he had previously praised Musk and Tesla.

"It's gross seeing so many root against Tesla. Be the person on the side of the climate and innovation, not the person hoping to make money on puts," Altman wrote in 2019. "Also, betting against Elon is historically a mistake...and the best product usually wins."

Musk wrote back at the time, "Thanks Sam!"

Musk sued Altman and OpenAI last week, accusing the company of jeopardizing its mission to benefit humanity by partnering with Microsoft.

OpenAI was founded by Altman, Musk, Greg Brockman, who was its chief technology officer, and several other engineers and scientists as a nonprofit, according to its website. Altman and Musk have had a complicated relationship and have exchanged jabs over the years.

OpenAI seemed to dismiss Musk's claims in the lawsuit in a memo sent by one of its executives, Jason Kwon, which Axios and Bloomberg obtained.

Kwon suggested the lawsuit "may stem from Elon's regrets about not being involved with the company today," according to the Bloomberg report.

Kwon, OpenAI's chief strategy officer, appeared to rebut Musk's lawyers' argument that OpenAI had become a subsidiary of Microsoft.

Kwon said, "We decide what to research and build, how to run the company, who our products serve and how to live out our mission."

He added: "We also directly compete with Microsoft to deliver the best value and products to businesses, developers and everyday people. As we know, OpenAI is the creator of ChatGPT and ChatGPT for Enterprise, while Microsoft offers Copilot and Copilot for Microsoft 365."

In a separate memo that Altman sent to OpenAI employees, he dubbed Musk a hero and said he missed when the billionaire used to compete by building better tech, Bloomberg reported.

OpenAI didn't immediately respond to a request for comment from Business Insider made outside normal working hours.