The United chief spoke out following his side's narrow 1-0 win, a game which had the Liverpool camp in uproar because of a penalty awarded after just a few seconds of the game starting and the sending off of Steve Gerard for a two footed lunge.
"It was a penalty," said Sir.
"Dimitar says he was definitely clipped. The replay shows he slightly touched him but the momentum is enough to bring the player down.
"There is no reason for him to go down anyway. He is not that kind of player.
"He is on the by-line, he is in the penalty box. I think it was right.
"As for the sending off, there was no doubt.
"It was two-footed and he was off the ground.
"Steven Gerrard is not that type of player but it was a reckless challenge. I don't think he left the referee with any option."