“I think this was not his job,” Herbert said. “I don’t think he’s a coach; he’s an umpire and he should stay on his chair for that.”

Roger Federer also made clear that he believed Lahyani had crossed a line.

“He was there for too long,” Federer said at the Open. “It’s a conversation. Conversations can change your mind-set. It can be a physio, a doctor, an umpire for that matter. That’s why it won’t happen again. I think everybody knows that.”

U.S. Open organizers elected not to suspend Lahyani from further duties at the tournament but did release a critical statement that said Lahyani’s conduct “went beyond protocol” and that he had been “advised to adhere to proper protocols in all matches that he officiates moving forward.”

Lahyani did not work any high-profile singles matches for the remainder of the tournament. But his primary employer, the ATP Tour, felt that a stronger punishment was in order. He is one of seven full-time chair umpires on the men’s tour.

“Despite the incident taking place at the U.S. Open, under the jurisdiction of the United States Tennis Association, the incident was still subject to ATP disciplinary action due to Lahyani’s position as full-time ATP employee and the high standards the ATP requires of its chair umpires regardless of the event to which he or she is assigned, in order to maintain the integrity of the Tour,” the ATP Tour said in a statement released after a request for comment from The New York Times.