Said Coleman after the game: "The referee is saying the momentum takes Ebanks-Blake off the pitch so when he re-enters he is not offside. If he is offside then he is offside - end of story.
"He comes on behind our defender and nods the ball in the back of the net. If he comes back onto the pitch then he has surely got to come back on in an onside position.
"I don't know where that rule came from, apparently that's the rule and the referee is sticking to it. We're disappointed with that.
"I'm not saying the referee has got it wrong, I'm saying whoever made the rule up has got it wrong. That's a ridiculous rule."
Nevertheless, Coleman was pleased with his side's display and felt they should have settled matters before the interval.
"When you're in a game like that and you're on top in the first half and not looking in any trouble, you have to kill the game off," he continued.
"We conceded at a bad time just before half-time, but we should have been two or three-nil up by then.
"We've played much worse than that and won. I'm not sat here disappointed we didn't get a point, I'm sat here disappointed we didn't get three."
City are now down to 13th in the table.