Colchester boss Phil Parkinson and Bradford manager Colin Todd will escape Football Association action after an incident in Tuesday's match.
Stewards separated the pair after Parkinson reacted to Todd's criticism of the U's tactics in the 1-1 draw.
Todd accused Parkinson of "killing the game as a spectacle," but Parkinson said: "I don't have to justify my tactics to anybody.
"He's looking for an excuse for his team's failure," he told BBC Essex.
"Colin will have had his scouting reports done, and will have had a chance to work on things to try to break us down.
"Rather than analysing his side's performance, he's looking to blame me and it's disappointing from a man of his experience."