Crouch caused problems for United throughout the contest and Ferguson suggested the tall frontman was getting away with committing infringements.
Ferguson said: "He fouls all the time. He gets off with it because of his height but he jumps on top of defenders all the time.
"He has been doing that for a long time. Referees know that. Even with the goal he has maybe caught Phil Jones, but he is right above him.
"He is a handful in the air, there is no doubt about that."