They had to be separated by the fourth official although neither manager received any punishment.
But Wenger's accusation that members of the Villa backroom staff spoke with Mason, when Arsenal were leading 1-0 through Denilson's goal, may well be placed under closer scrutiny as it could be viewed as an accusation of improper behaviour.
"I know exactly how it works here," Wenger said after seeing his side lose their 2-0 lead. At half-time the referee gets stick and in the second half, every 50-50 decision went to them.
"I decided to wait and see what happened after half-time and I was not disappointed. It is not only at Villa where it happens. I don't feel the need to elaborate any more."
The draw left the London club 10 points behind leaders Liverpool ahead of Wenger's reunion match with former Arsenal captain Tony Adams on Sunday.
"We are disappointed, but 58 out of 59 experts had us down to lose the game today," Wenger added. "What happened with Martin O'Neill was nothing. The dug-outs are very close at Villa. You will have to ask him why it happened."
O'Neill meanwhile was less than impressed with Wenger's accusations.
He did not deny that there was a conversation between his longstanding assistant John Robertson and Mason, but said: "There was someone speaking to the referee at half-time. It was John Robertson and he simply asked the referee to explain a decision in the build up to their first goal.
"Gabby Agbonlahor was fouled. He was obstructed, but the foul was not given before they scored. John Robertson asked him to explain why and the referee chose not to. There was no one giving him stick. Arsene Wenger has his own opinions about it.
"As for what happened in the dug-outs, that was much ado about nothing."
Wenger still believes his side can mount a serious title challenge, despite remaining three points out of the top four, behind O'Neill's men, because of Villa's late fight back through Gareth Barry's penalty and Zat Knight's stoppage-time equaliser.
"We believe we have the quality," said Wenger, who saw Abou Diaby score a well-worked second goal.
"Of course we can still win the title. We have played against Villa, Manchester United, Chelsea and Liverpool and Villa are the only team to beat us. We can take confidence from that."