Elon Musk is proving to be a difficult owner to work for, even for X CEO Linda Yaccarino, single-handedly torpedoing a high-profile contract she secured.

Yaccarino is in the unenviable position of being tasked with turning around X’s fortunes, building up ad revenue that has taken a major hit since Musk bought the social media platform. Unfortunately, Yaccarino is learning first hand that Musk may well be the biggest obstacle to her successfully doing the job she was hired for.

According to The New York Times, Yaccarino brokered a deal that would see former CNN anchor Don Lemon bring his web-based show to X. The deal was a big win for Yaccarino, with Lemon’s being the first high-profile, mainstream show to move to X and support Yaccarino’s vision of diversifying X’s content by providing more traditional programming.

Unfortunately for the executive, Musk was Lemon’s first guest and the interview did not go well. Throughout the interview, Musk became increasingly testy in response to questions he didn’t like. The next day, the Times reports that he sent a message to Lemon’s agent saying, “Contract canceled.”

A single uncomfortable interview and Musk undid all the work he hired Yaccarino to do, further cementing his reputation as a petulant executive who responds impulsively.

Musk is increasingly being blamed for Tesla’s dropping sales, with many seeing the executive’s antics as an unwanted detriment to attracting new customers. It seems Tesla isn’t the only company suffering from Musk’s behavior, with X turnaround plan in jeopardy as a result of his actions.

Yaccarino is already had to smooth over dealings with Google after Twitter stopped paying for the cloud services it was using. With the CEO’s work now being undone by Musk, it wouldn’t be surprising if her days at the top job were numbered, and she chose to exit for better opportunities. No matter how much she may have prepared for the challenges of being X CEO, she probably didn’t imagine her boss directly undermining her efforts.

UPDATE: Don Lemon has sued Elon Musk and X, alleging breach of contract and accusing the company of misappropriating his name and likeness.