Speaking to reporters after the match, Coleman claimed that Hooper ruling in favour of the Owls cost his side the game.
"Performance-wise, there isn't much more I could have asked of them. They did more than enough to come away with a result," he said.
"I have sat here many times and not been able to say that because we hadn't performed but I couldn't say that today. You can fault the referee, though and I never blame referees for results, I don't. But I thought he was short today.
"The penalty incident was a defining moment; we get a penalty, they go to ten men, and we end up with nothing. That was hugely disappointing. "I can't understand why he didn't make the decision."
The defeat leaves Sunderland second-bottom of the Championship, five points away from a position of safety with six games left to play.