Celtic's Kristoffer Ajer was "laughing and winking" at red-carded Sam Cosgrove while lying on the ground, said Aberdeen manager Derek McInnes.
The Dons manager also revealed Celtic counterpart Neil Lennon agreed Cosgrove should not have been sent off in his side's 2-1 defeat to the champions.
Aberdeen striker Cosgrove was shown a straight red card after 69 minutes for a challenge on Norwegian Ajer.
"100% we will be appealing against the decision," McInnes told BBC Scotland.
The dismissal for Cosgrove, who had earlier cancelled out Christopher Jullien's strike, came three minutes after Odsonne Edouard had restored Celtic's lead as Aberdeen fell to fourth place in the Premiership.
The striker won the ball before his trailing leg caught Ajer on the follow through.
"I have watched it 20 times and Cosgrove has won the ball cleanly," McInnes said.
"If he goes in at speed and hits the player at any point then you could understand maybe the referee sending him off. When you go in at speed like that you have got to make sure you get the ball and 100% it's a brilliant tackle.
"He probably doesn't need to go in as quick as he does but he has won the ball cleanly. It's a brilliant tackle.
"And then you've got big Ajer winking at him and laughing at him lying on the ground. There's nothing wrong with the boy. The boy carries on, I didn't see anything wrong with him, he is running about."
And McInnes, whose side have now only won two of their last six games, said Lennon told him "no way was it a red card" after the game.
"I've been asked if it's like Ryan Porteous' challenge [against Rangers for Hibs on Friday]," he said. "It's nothing like Porteous' challenge."
Celtic 'could have won by more'
Celtic assistant manager John Kennedy felt Cosgrove had been taking a risk with his challenge.
"I don't think he fully catches him, he just nicks him," Kennedy said.
"But in the modern game when you fly in at that speed, and you leave the ground, and there is a form of recklessness about it, you give the referee a decision to make and in his eyes it was a red card. So that's up to him."
Celtic had 28 efforts at goal to Aberdeen's two and Kennedy always felt the winner was coming as he side moved five points clear of Rangers at the top of the Premiership.
"It could have been a more emphatic win," he told BBC Scotland. "Our last few games have been like that - the scoreline hasn't reflected our chances created and quality of play. In terms of performance, we can't ask for much more."