Shelvey's red card provoked a furious reaction from the Liverpool midfielder, his team-mates and the home support, but Sir Alex was unwavering in his assessment of the youngster's lunge on Jonny Evans - and he shrugged off Shelvey's finger-jabbing tirade towards the United manager as he left the field.
"I think it's a clear sending off, I've absolutely no doubts about it," said Sir Alex. "I've seen the replay. It was reckless. Jonny Evans, who has dived in, went for the ball and got the ball, no question about that, but Shelvey was nowhere near getting the ball and could have given Jonny Evans a real bad injury. He was very lucky, actually.
"He (Shelvey) came and blamed me. Why not? Why look at himself in the mirror? Just blame someone else. I think the boy's young and when he looks at it again he'll realise the stupidity of it. He may apologise, he may not." Shelvey later Tweeted that he had apologised to the United manager.
Despite the dismissal, it took Steven Gerrard's opening goal to spark United into life, and the boss was full of praise for Rafael's superb leveller, and the nerve shown by Robin van Persie, scorer of the match-winning penalty.
"[Rafael's goal] got us out of the mire," he said. "It was a fantastic goal, a good bit of football and it put us in the position where we didn't need to panic and worked our way through the rest of the game. It wasn't easy for him [van Persie], but he's taken it well, just the way I envisaged he would take these penalties. When he was at Arsenal, either side he would thunder them home. [Pepe] Reina's had a good attempt, he got a hand to it, but the power of the shot has made it safe."