Hickey saw red on 17 minutes for his late lunge on Mert Muldur, but other than the Francesco Caputo equaliser, there were no more goals.
“The game was affected by the red card, which I want to say, in my view was not a red card. Unfortunately, we too have paid for incidents like that with the rules as they currently are," De Zerbi told DAZN.
“I am always honest, when it's in our favour or against us. Anyone who has played football cannot think that is a red card offence. Hickey was late, but Muldur had prodded the ball away and that makes it look much worse. He was going for the ball and the ball had gone. It always looks worse on a replay or a still image, but it was a natural movement.
“If you look at everything that happened after that, we had 31 attempts on goal, but Bologna just defended, whereas with 11 men they would've attacked and caused us problems. It would've been an entertaining, open game."