The United boss claimed Luiz elbowed his fellow Brazilian, who kicked out at the Chelsea defender to earn a straight red card.
United had just fallen behind to a Juan Mata shot which deflected in off Phil
Jones when Rafael took exception to Luiz attempting to protect possession and clattered straight through the back of his compatriot.
"Luiz has actually elbowed him twice," said Ferguson. "It is quite clear on the camera.
"Whether the referee will do anything about it I doubt very much, Howard Webb won't be bothering himself about that.
"Rafael was certainly elbowed, but you know what happens when a player retaliates. He gets punished the most. That is what happened."
Ryan Giggs was fuming at Oscar for waving an imaginary card, which sparked a melee between the two sets of players, while Luiz was pictured rolling about, seemingly in agony, but actually with a broad grin on his face.
"It is bad isn't it? It's not very professional," Ferguson added. "He (Luiz) rolled about. You see that a lot with foreign players. He did roll about and made it look worse.
"To be honest, I don't think the referee has seen it. He has been convinced by
On the game, Ferguson admitted that his side were far from their best but feels referee Howard Webb did them few favours.
He told Sky Sports: "The team took their foot off the pedal. There was no edge to the game all day. I think Chelsea deserved to win.
"Unfortunately it was controversial, it always is when we play Chelsea, but we can't complain because we didn't play well enough.
"It was a bit of a lucky goal, it has deflected off Phil Jones. I can't make any excuses in terms of the performance. Certainly refereeing decisions went against us. They surrounded the referee all day, four or five players all the time."