Twitter has seen thousands of layoffs, departures, and resignations since Elon Musk took over, but one of the latest staffing changes appears to have been personal — the company’s new CEO tweeted that Eric Frohnhoefer, an employee who had publicly argued with him on the platform, had been fired.

The saga started on Sunday, when Musk tweeted an apology for Twitter being slow in “many countries” and implied that the poor performance is because the app does over 1,000 “poorly batched” remote procedure calls to load the home timeline — basically saying the app has to reach out to other servers a bunch of times and wait for a response for each request. Frohnhoefer, who tweeted that he’s spent six years working on Twitter for Android, quote retweeted Musk’s statement saying it was incorrect.

According to Frohnhoefer, Twitter actually makes zero remote procedure calls, or RPCs. Instead, he says, when the app starts up, it makes around 20 background requests. Seemingly to clarify his original tweet, Musk then responded, “The fact that you don’t realize that there are up to 1200 ‘microservices’ being called when someone uses the Twitter app is not great.” Frohnhoefer disagreed again, tweeting that the “number required to generate the home timeline is closer to 200 than 1200.”

Elon Musk eesponded that the engineer was fired.