Jacob Coxon is an ex-OpenAI and Anthropic employee who resigned and warned about AI.

What we found

Supports. The AP report says Coxon, who spent three years doing research at both Anthropic and OpenAI, resigned from Anthropic over concerns that AI firms are not acting responsibly.[1][3]

Supports. Reuters describes Coxon as a former Anthropic researcher who quit the company over safety concerns and warned AI could kill us all by the end of the decade.[2]

Supports. Time reports that Coxon's viral post said 'I resigned from Anthropic today' and that he had spent three years on pretraining research at both OpenAI and Anthropic.[4]

Supports. Several outlets, including Politico, NZ Herald and Newsweek, describe Coxon as a former OpenAI staffer who joined Anthropic, resigned, and warned that AI firms are gambling with lives.[5][6][7]

Context. The post's phrasing 'ex open AI and Anthropic employee' matches the sources' account of the employment history, so the extraction adds nothing the passage does not say.

Sources

7 sources: 2 fact-checkers, 2 tier 2, 3 not rated

1. 1Anthropic researcher resigns with warning about the dangers of AIapnews.com · fact-checker · cited for: supports
2. 2From hallucinating AI chatbots to wiping out humanityreuters.com · fact-checker · cited for: supports
3. 3Anthropic researcher's resignation sends warning about the dangers ...pbs.org · tier 2 · cited for: supports
4. 4The AI Tipping Pointtime.com · tier 2 · cited for: supports
5. 5AI researcher quits Anthropic with dire warning about safetypolitico.eu · not rated · cited for: supports
6. 6‘Gambling with our lives': AI researcher quits Anthropicnzherald.co.nz · not rated · cited for: supports
7. 7Who Is Jacob Coxon? Anthropic Researcher Quits—Warns AI Could ...newsweek.com · not rated · cited for: supports

Where this claim was made

Said in 1 published post

• The Ebro, Laura, Rosenberg Show · Sep 12, 2026“Ah, this this tweets or series of tweets that went viral, ah, came from Jacob Coxon, who is an ex open AI and Anthropic employee, ah, and he resigned, and he warned that AI”Post →

Related claims

• Jacob Coxon is a former employee of OpenAI and Anthropic who worked in pre-training research for three years.True
• OpenAI workers have quit and warned that the founders' work could kill us all by the end of the decade.True
• The CEOs of Anthropic, OpenAI, and XAI stated that AI development should slow down.True
• OpenAI's security team was unaware that AI agents they created were communicating with each other to attempt to exit their sandbox environment.Mixed
• Anthropic CEO Dario Amodei and OpenAI CEO Sam Altman testified at the UN Security Council.True