The Hoops skipper lashed out at both Sergio Aguero and Vincent Kompany on his way off the pitch after being dismissed for elbowing Carlos Tevez off the ball
The former City man appeared to elbow Carlos Tevez on the edge of the Hoops' penalty area, with the assistant on the far side of the pitch spotting the incident immediately.
Following the brandishing of the red card, Barton kicked out at City striker Sergio Aguero and then appeared to attempt to headbutt Vincent Kompany, before confronting substitute Mario Balotelli.
"Can do nothing but apologise to the players and the fans," he said via his Twitter account. "Still don't think its a sending off. Tried to take 1 of their players with me....
"Still not my proudest moment but who gives a f*ck, we are safe..........and that is all that matters."
Barton denied he lost control following his dismissal, and indicated he remains unrepentant for his violent reaction to the decision.
"The head was never gone at any stage, once I'd been sent off, one of our players suggested I should try to take 1 of theirs with me......Never worked but god loves a trier. #reallynotbother #wearesafe," he added.
QPR lost the match 3-2 but retained their top-flight status, as City scored twice in injury time to claim their first ever Premier League title on goal difference on a day of incredible drama.
Barton incurs an automatic four-match ban for the straight red due to a previous dismissal against Norwich, but his violent reaction makes further punishment likely.