Cameroon was never up to it. Mexico dominated, even domineered events on the pitch. They played more then decent football, exposing Cameroon's vulnerability in defence and mid-field, and the final scoreline is not doing service to the real quality-gap between these two teams. It could have been much worse for Cameroon, hadn't they been hugely assisted and thus rescued, by ar1, and to a certain degree - by the ref. himself.
Mr. Clavijo, ar1, who had been assisting Oscar Ruiz in WC 2010, had a horrible day. It started from kick-off and got worse durinthe first half. Fortunately for him, the contest was so one-sided, he had not much to do wrong during the second half. It all started in the second minute: Assou-Ekotto pushed a Mexican player close to Mr. Clavijo, but astonishingly, the ar awarded Cameroon with a free-kick. two minutes later, a Mexican attempt to cross the ball inti Cameroon's penalty-area, was deflected by Assou-Ekotto, but the ar, perfectky positioned and clear sighted, awarded a goal-kick instead of a corner-kick. Then Clavibo ruked dos Santos offside (11'), disallowing the goal he scored. I think the ar should be given the benefit of the doubt: although the replay suggests the player was parallel to the last defenders but the goalie, it a terribly close call, and in cases like these the ar might get away with his decision, whatever it has been. But this was not the end of it. The huge mistake waited "around the corner (kick)". In the 29th minute Mexico delivered a corner-kick from their left-hand side. The ball was headed in the Cameroon penalty-area, thus lengthening the cross and reaching dos Santos on the right, close to the edge of the goal-area. He scored just to realise he was adjudged offside and the goal was disallowed. The main problem with that decision - the cross-distance was lengthened by a Cameroonian header (which should have been detected by Mr. Roldan!). Secondly, even had there been a Mexican header, a Cameroonian player played dos Santon on-side as he, as well as his goalie, were closer to Cameroon's goal-line than the Mexican forward. Clavijo was so perplexed from then on, thus not flagging for a Mexican offside when there was an obvious one (40'). Mr. Diaz demonstrated a wholly different offside approach. When he was the one to decide Mexican offside/onside positions, he rarely decided the former. Thus one remained puzzled about the instances where no flag was raised in the second half, while no replay was provided to have a better and more comprehensive view (60',63', 73', 81').
Mr. Roldan is in great shape, close to the action, but well-positioned to get into players' way. he made some mistakes of his own, and in other cases was party to his ars' mistakes, concerning throw-ins (direction and application of the two-hands rule) and corners/goal-kicks (e.g. 4', 6', 18', 22', 25', 45'). There some mistakes in foul detection or direction (e.g. 4', 10', 26', 48', 52', 76'). I would mention two cases in particular. In the 54th minute, Peralta (later, to score the Mexican goal, 61') came much closer than 9.15 metreswhen a Cameroonian free-kick was taken without any reaction from the ref. In the 52nd minute, M'Bia hit an opponent blatantly in his face while running for the ball. Unfortunately for the ref., who was the closest on earth to the incident, he was positioned behind the Mexican's back. "feeling" there was a foul, the ref. penalised Cameroon, but not seeing exactly how the foul was committed - prevented him from duly cautioning the culprit. Finally, and certainly worst of all - Mr. Roldan of all people, should have seen (29') that the ball reached dos Santos due to a Cameroonian header, and hence - oerruled his hapless ar and allowed the goal to stay. Saying all that, Mr. Roldan had a second half much calmer and more balanced second half, which enabled him to demonstrate some of his positives he had been renowned for (coolish attitudee. clever use of the advantage rule)