Very good work
First of all, the positive things
His approach and style were very adequate for this match, even though the players - that has to be emphasized - were more friendly towards the ref in comparison to e.g. Iturralde's match or the one of the German Stark last season. The yellow cards he issued were totally justified, only one time, it had some red spots on it, that was Ramos' foul on the near sideline, but red would have been probably a bit too harsh.
Offside...
It was not very obvious, as I have already mentioned. Prior to the 1-2 (own goal by Marcelo), a Barca striker was alone in front of the goal and received a pass by Messi, the Real defender had to interfer, had to make a jump on the ground to clear the ball, his action was however not under control, it was some kind of rescue action. The ball appeared in front of the Barca striker who then scored the goal with the aid of Marcelo. BUT: the striker who should have received the initial pass was in a 1 metre offside position, the defender merely had to behave like this because he knew that there was someone who could have received the ball, hence, his behaviour was influenced by the striker being in an offside position. You see, hard to see, but the rule which was changed in this field by FIFA at the beginning of 2011 is clear.
Match, again 90+3 and Messi
My bet was a 3-1 for Real. The gap between both teams got smaller, Real was the favourite, after 22 seconds, Benzema managed to score, but what did then happen then? The Barca way to play football, like handball, moving around the box, 65-70 % ball possession and a brilliant Messi who was however lucky not to be sent off in the 43rd minute. If Fernández Borbalán had been consistent in his previous line of issueing yellows, he should have sent him off. And again it was the 93rd minute when some troubles came up but everything was well solved...What remains is a very positive impression we could receive from him and I think that his promotion on UEFA level is only a question of time. ¡Bien hecho!