He then ran onto the pitch and told referee, Wayne Barnes, he needed to take Atonio off for a head injury assessment [HIA].
There was an agonising end to the RBS 6 Nations for Wales as they were finally beaten in the 100th minute of a weird match in Paris as France finally conjured up a match-winning try after a stream of penalties.
The process that occurred prior to him warming up before going back on, one of their coaches went outside the technical area, had a word with their doctor and within a minute of that, he went on and took their tighthead off.
Maestri added that Barnes' failure to award a penalty try showed he had lost control.
If a French player is found to have bitten North he could be banned for up to 15 weeks and acting Wales coach Rob Howley said: "It's gone to the television match official". It's down to the referee to spot it.
The clock showed 99 minutes and 55 seconds when France's replacement flanker Damien Chouly touched the ball down after nine penalty scrums and Camille Lopez slotted over the conversion to seal victory for the hosts.
"It was verging on nuclear warfare on the sidelines and the referee didn't react", he said.
But there was controversy over the 84th-minute substitution of Uini Atonio, France bringing preferred tighthead prop Rabah Slimani, known for his devastating scrummaging power, back on to strengthen the set piece. Howley believes it was a tactical switch, which is against the laws of the game.
Indo-Pak Indus Water Commission conference to today begin in
According to Pakistan, designs of the three projects are not in line with the treaty, whereas India has maintained otherwise. India had suspended the annual PIC talks in Sept 2016 - ostensibly in wake of Uri attack in Occupied Kashmir.
France forwards coach Yannick Bru, however, was pleased his players did not let frustration get the better of them.
In the end his patience paid off and the constant French pressure forced the try - there was certain inevitability about it although a distraught Dan Biggar was one player who clearly felt it was a huge injustice.
Injury time went on so long that the kickoff in Dublin, where Ireland beat Grand Slam-chasing England, was delayed.
"Two wins from five isn't good enough". Barnes warns Warburton, 1:07 left on the sin-bin.
Thrilling: France celebrate their late, late win over Wales. But they managed to weather the storm and by half-time were back in touch thanks to three penalties from the unerring boot of Leigh Halfpenny.
"In the event that he wishes to make a citing complaint in respect of the alleged bite (or any other incident), because he considers that there was an act of foul play that warranted a red card, he is required to do so within 48 hours after the conclusion of the match (although in certain circumstances, for example where he is uncertain as to the identity of the player (s) concerned, he is permitted to make his citing complaint after the 48-hour deadline)".
There's no conclusive evidence of a bite so play will restart with yet another scrum from the France penalty.