Chelsea manager Jose Mourinho threatened to walk out of his post-match press conference when quizzed on Branislav Ivanovic's alleged headbutt in Wednesday's stormy encounter at Stamford Bridge.
The Chelsea defender could race retrospective action after grabbing Everton midfielder James McCarthy by the neck and appearing to thrust his head into him during a melee sparked by a red card shown to Gareth Barry.
Minutes later, Chelsea went onto score an 89th minute winner through Willian.
Mourinho, who was last month fined £25,000 for claiming there is a 'clear campaign' against his side, was in no mood to discuss the incident in his post-match press conference, however.
"I'm concerned with my reaction, because one more question I leave," he said. "And after that you are not happy. The next question for that story I have to go."
The Chelsea boss had earlier told BT Sport "don't make me laugh" when asked if Ivanovic had aimed a headbutt at McCarthy. He cut short a further interview with BBC Sport when asked if he would punish the player if replays suggested wrongdoing, saying: "Sorry, see you tomorrow."
Everton manager Roberto Martinez made no secret of his disgust over the referee's decision and accused Chelsea players of influencing what he believed to be the turning point in the game.
"Ivanovic's behaviour is wrong. He grabs McCarthy around his neck in a very forceful manner then puts his head against him. James doesn't react a single bit," he told BBC Sport.
"If you want to be on top of the law that's a red card and we got nothing out of that moment.
"Every time a player loses a challenge it feels like the weight of the world is on the referee's shoulders and he feels he needs to react. To give Barry a second yellow card because of the reaction from Chelsea's players is disappointing.
"They surrounded the referee and their conduct was a real shame. It created a little bit of belief for Chelsea and the goal came as a consequence of that. It was a very scrappy goal - if you don't have the momentum often they don't end up in the net."