United were leading 2-1 on aggregate against Spanish giants Real thanks to a Sergio Ramos own goal, when Turkish official Cakir showed the Portuguese winger a red card for a high challenge on Alvaro Arbeloa.
Nani was in the process of trying to control a ball dropping over his shoulder and did not even appear to be aware of Arbeloa's presence prior to making contact with the Spaniard.
United went on to lose 3-2 on aggregate and Laudrup said: "I watched the game the other day and I am not a supporter of Manchester United or Real Madrid, but it should never, ever have been a red card.
"A yellow card maybe, but a red card? Absolutely not.
"I don't think it matters whether it's a referee in the Premier League, La Liga or a Champions League game.
"It was just a bad decision. Referees are human and make mistakes - there is no problem with that - and sometimes it goes against you.
"But we are allowed to say when a referee gives a poor performance, and that was a very poor decision."