The Turkish official made all the headlines for giving Nani a straight red for a high tackle on Alvaro Arbeloa in the 56th minute at Old Trafford.
Madrid, who were trailing 1-0 on the night, then scored twice in 13 minutes to secure a 3-2 aggregate victory and progress to the quarter-finals of the competition.
United boss Sir Alex Ferguson and many of his players were furious at the decision.
"It's hard to keep your faith when you see what's happened in the last few
years," said Ferguson on Friday morning. "It's the third time we've been knocked out by a referee's decision and it's not easy to take."
Cakir has sent off seven players from English clubs in European competitions, including Chelsea captain John Terry and Mario Balotelli whilst he was at Manchester City.
And Ferguson - who was so upset on Tuesday night that he refused to attend the post-match press conference - said he was well aware of the statistic: "I was concerned before the game. I said that to my staff. I had a big worry about it."
But Cakir insists his conscience is clear and said: "I feel fine and don't doubt my decisions. The red card shown to Nani was correct. The world will recognise the truth with time.
"I doesn't make me very sad. I just don't think about it," Cakir added. "I have received more criticism on previous occasions, but I have always got back up and come back.
"I can do so again. I try to do my job correctly and I am doing well. I need to continue like this. I do my job perfectly."
Dcspur, "when pressuring officials is used as a legitimate tactic", because of course only United do that. Certainly not Real...- redgenesis