Chelsea found the winner in the 87th minute via a Juan Mata shot deflected off Phil Jones, but Fergie was fuming about an incident two minutes later.
As United chased an equaliser, Rafael and Luiz tangled in the corner of the field. Luiz appeared to hold his compatriot off with an elbow, who responded by kicking out at him. Luiz fell to the ground and was seen on camera smiling as referee Howard Webb blew his whistle to send Rafael off.
Ferguson said after the match that Luiz's play-acting had been instrumental in the referee issuing a red card, and that it was an unwelcome trait in non-British players.
"The ref has been bought by the fact Luiz is rolling about," he said. "But whether the ref will do anything about it, I doubt very much. When a player retaliates he gets punished the most. Luiz rolled about. You see that with these European, foreign and South American players.
"He [Da Silva] retaliates but Luiz quite clearly elbows him twice, then rolls about like a diving swan and that convinces the referee. He was smiling. It's bad. What kind of professional is that? He [Da Silva] was elbowed and he retaliated. That's what always happens, the player who retaliates always gets the bigger penalty and it was clear that Luiz elbowed him twice.
"It was rash what he [Da Silva] did, he's a young lad and should know better but retaliation never works. I wouldn't say it was violent conduct. The referee hasn't even seen it, I don't think he could see it at all. But he has gone with the fact that Luiz has rolled about on the floor and I think that convinced him it was a red card."
- Sports & Recreation