Congratulations to Madrid for going through. The red card was a poor decision and I do think United would have gone through if Nani wasnt sent off but the way in which Madrid took advantage of their extra man and played the rest of the game was superb. Annoyingly it is looking increasingly like it could be Madrids year, although I think there are a couple of teams left in the competition who could give them a real tough time, especially a strong counter attacking team like Juventus.
Edit: In relation to the ref, I think we have to remember he screwed up for Madrid's disallowed goal as well. No way was it a foul.