I thought this semi-final was going to be officiated by an European ref. Well, fortunately I was wrong, because Vázquez was finally the best choice. A game between Brazil and Argentina is always special and nobody could know this better than an Uruguayan referee. Vázquez knew that he would have to work in a heated climate (and not only because of Beijing summer) but also that he was refereeing a match where the two biggest South-American country-teams were going to fight for a place in the Olympic final.
Vázquez and one of his assistants decided that the 2nd Arg. goal was legal, and it was: Agüero was behind Brazilian player Nº3 line. The referee and the other lineman decided to invalidate a Brazilian goal, and they were also OK: Pato was slightly off-side. Vázquez also decided to concede a penalty to the Argentinians, and he was, again OK: Agüero was tripped by Breno. The referee did everything well here.
During the 2nd half Argentina was superior. Brazilians get nervous when another team does what they use to do: playing a nice football, making the fans enjoy, and scoring one, two, or three goals. Brazilians doesn´t know how to loose. And they often do what they did here: hitting the other team players. As a result of this, Lucas and Thiago Neves were perfectly sent-off by Vázquez after two terrible kickings against Mascherano.