Djokovic's camp was at its boisterous best in both matches, which did not sit too well with Federer. And the Swiss legend made that fact known during their Monte Carlo match when leading 3-2 in the first set.
Djokovic, who was serving to make it 3-3, struck a return that was called 'out' by a linesperson. However, replays showed that the ball landed on the line.
Meanwhile, Djokovic's camp - including father Srdjan and mother Dijana - seated right behind Federer began yelling towards the Swiss, asking him to check the mark.
As Federer began walking towards the spot where the ball landed, he turned towards Djokovic's parents and said "be quiet, okay," before cleaning the mark.
Below is a video of the incident from a recent tweet which has since gone viral:
A longer version of the incident from the match can be viewed in the YouTube clip below:
The point was replayed and eventually went in favor of the Serb even though Federer thoroughly dominated the rally. Federer pocketed the opening set 6-3 and led 3-2 in the second before Djokovic retired due to breathing difficulties.
Neither Novak Djokovic nor Roger Federer was asked about the Swiss' comment during their respective post-match press conferences
While Federer's remarks have remained fresh in the minds of many fans even 14 years down the line, strangely enough, neither player was asked a question about the incident during the post-match press conference.
Djokovic was mainly quizzed about his ailment and the Serb revealed he had been suffering from a "sore throat" in the build-up to the match against Federer.
"Well, I didn't feel good for last three days," Novak Djokovic said in his post-match press conference. "I've been waking up with some sore throat. But I thought it's not going to be nothing special."
The Serb added that playing someone of Federer's caliber aggravated his condition.
"But obviously when you're playing against the No. 1 player of the world, you obviously get a lot of balls back and longer points, and I just couldn't get enough energy back after each point," Djokovic added. "I needed a lot of time. And I just decided not to risk anything."
Upon further probing, the current World No. 1 revealed that he also suffered from bouts of dizziness.
"Well, it's a sore throat. I feel dizziness a little bit in the last three days," Djokovic said. "I don't know. Doctor in the tournament couldn't give me the right diagnosis. I'll check as soon as possible."
Roger Federer, too, was probed about Djokovic's illness. However, the Swiss admitted he did not think the Serb was physically compromised until he summoned the doctor.
"No. I didn't see anything anyway from my side till when he called the doctor," Federer said during his press conference. "It made me remember that, you know, he really sort of had at 40-Love at 5-3, I think it was, he just let his head hang a little bit. I thought that was more in disappointment, you know. So maybe it was more also because of the sickness. I don't know."