This is a result that will scar them for a very long time. They came into the game feeling smug but left on the back of getting hammered 7-0 (SEVEN). Whether they admit it or not, the pain of getting humiliated like that against their biggest rivals is even more intense from the joy they got from winning the League Cup.
And there are no valid excuses. They finished the game with 11 men and all their best players started. This is one of their best seasons since Fergie left and one of our worst since Jόrgen came. The cocky attitude before the game made it even sweeter.
Imagine losing 7-0 to a team that is going backwards as Ferdinand implied. The level of embarrassment is so much that they'd rather deny it. Instead, they'll channel their bitterness into hoping that we lose/drop points in our remaining games but every positive thing that we do will be another dagger in their hearts.