Newcastle United manager Steve McClaren and his Manchester United counterpart Louis van Gaal disagreed on the early penalty awarded against Chancel Mbemba in Tuesday's 3-3 draw.
A thrilling and controversial clash at St James' Park saw its first goal arrive after only nine minutes when Wayne Rooney scored from the penalty spot.
The penalty came after referee Mike Dean had penalised Newcastle defender Mbemba for handball as he attempted to block a Marouane Fellaini header from close range.
McClaren felt the decision was ridiculous, but Van Gaal is certain it was a spot-kick and does not feel there should be a discussion over the decision.
"I could not believe it," said McClaren. "The first goal against top-four teams is absolutely vital and when no-one appealed and everyone just walked away, we could not believe it was a penalty.
"We had such a good start. We were composed; we were keeping the ball and creating chances and all of a sudden [it came] from nothing.
"Nobody appealed, nobody even tried to. I have looked at it, he [Mbemba] just goes up and the momentum of where his hand goes, it hits his hand. He is about half a yard away - how can he get out of the way?
"It is ridiculous and the team could have gone under after that, but credit to them - they kept fighting."
Van Gaal, though, told BT Sport: "I have seen it. When you want to avoid a header of Fellaini by [putting] your hands to the ball I don't think that is a discussion.
"I don't think it is ball to hand, it is the hand to the ball and Fellaini cannot head it. You never know in this world - you can always have a discussion - but I don't think so."