The sending off was harsh but his foot was very high and if you look at the laws the ref was within his rights to send him off. Real were controlling the game at the time though, after Man U scored they upped their game, though the sending off obviously made it easier for them. It still took a great strike from Modric to level it though, overall Madrid didn't play how they can though.
Ronaldo was off his game, at times it was almost as if he felt bad for playing against Man U. In addition Real had a perfectly good goal chalked off when the ref adjudged that Ramos fouled RVP in the box, it wasn't a foul.