"It was clever play by Petrov. He angled his leg and there was no way it was a penalty. It must have been a difficult decision to make in front of the Holte End!," Coleman said after the 1-1 draw.
"Obviously we were disappointed with the decision but we came back well. It was not pretty stuff to watch but we always made it difficult for Villa and they rarely looked settled.
"They are flying at the moment and they are a new team under Martin O'Neill's control."
Coleman claimed that Fulham's improved away record this season is due to their change of match preparation which appears to be working well at the present time.
He added: "We now travel as much as possible on the day of the game to allow the players to have more time at home.
"It certainly seems to be working for us as we've already got as many points away from home as we did in the whole of last season."