Hurkacz approached Dimitrov at a changeover in the third set with the Bulgarian about to serve at 5-6, asking him if he wanted to replace Alison Hughes while motioning to do so.
Seemingly unhappy over a line call, eighth seed Hurkacz had called multiple times for the supervisor before suggesting to Dimitrov they get a new umpire.
No change was made and Dimitrov held serve before winning the tie-break to advance 7-6 (7/5), 6-4, 7-6 (7/3), reaching his first Roland Garros quarter-final at the 14th attempt.
Hurkacz downplayed the incident after the match, insisting it was "all good".
"It's clay court, so it's sometimes difficult when the balls are really close... just it's really close from time to time," he said.
"Definitely some of the calls you wish they are different way, but it's just the way it is, and you gotta accept the things."
Dimitrov defended Hurkacz and maintained the exchange was not a big deal.
"I think the thing is we all can say very difficult things in the heat of a moment. I'm sure whatever he said, it was not meant in a bad way," said Dimitrov.
"Also, the umpires, they're trying their best. It's a tricky business out there when the ball gets so close to the line."
