Rivera started this match determined to book nobody, at least during the 1st half. At the beginning, the game helped him: his whistle sounded for the first time at 10´... no violent actions, and calm players. But after 30th minute, it got normal... some faults, tricking, and talks. Apparently, this last part wasn´t inside Rivera´s plans.
It´s OK to start your refereeing trying to let the game flow, but Rivera took this idea too seriously... He should have booked at least twice during the 1st half, but he didn´t. In contrast, he used a strange technique in order to "punish" violent actions: instead of booking, he ran from his position - looking angry - to the place where the fault had been commited. His plan could have been effective ... but it wasn´t.
The absent Red
Rivera biggest mistake happened at 60´, when Ronald Gutierrez sent Cambiasso out after violently kicking him in one of his ankles. The argentinian player was substituted by Fernando Gago, but Gutierrez get an insufficient yellow. This action demonstrates how Rivera´s job was: too permissive. And Cambiasso still has Gutierrez´s foot inside his ankle.