As ever, Benquerenca had trouble with judging foul play. He gave 39 free kicks, which is simply too many. About a third of these were either wrongly awarded after fair tackles, or given for the most minor contact. He missed some bigger fouls, particularly on Barca. He played two good advantages, but on the whole applied it poorly by stopping the match when players wanted to go on and not bringing play back when no advantage materialised.
Given that trivial contact resulted in a free kick all night, it is amazing that he did not point to the spot when Alves was clearly fouled by Sneijder. He then compounded the error by cautioning Alves for diving. At least Alves was able to see the funny side of this comical decision from the referee.
Apart from the booking of Alves, the other cards were all very much warranted. Players must know by now that if they kick the ball away the referee has to book them, there is no room for discretion and it is pure stupidity to get a booking for that. The card for Puyol was correct, after a cynical block. However, Benquerenca didn't reach for his card straight away, and seemed to be influenced into the decision by a crowd of Inter players. This made him look weak.
He tried very hard to maintain control of this match. His signals were clear and forceful, his whistle loud and commanding, his cards threatening. But because he got so much wrong it appeared like he wanted to be the star of the show, and that he was overly flash. His assistants did not help, getting a number of offside decisions wrong, including allowing Milito to score from an offside position.
This was always going to be a difficult match, and it is a shame that Benquerenca had to be forced into the limelight. He clearly isn't quite good enough for this stage of the competition, but UEFA have so few referees who are good enough that some matches have to suffer. It is, however, madness that Claus bo Larsen is stuck in the Europa League when he is one of the few who could actually handle this match.