Argentina and Mexico was a fantastic game, it had everything, talent, drama, dodgy decisions and a fantastic winning goal. There were a couple of potentially (or actual) game changing decisions. First, the referee gave a yellow card to the wrong guy. Secondly, there was a yellow card awarded for a foul when a red was warranted). The ref pointed to another defender saying that he was the last defender... he could not have reached the attacker in time. Thirdly there was a shot on goal (from Mexico, I think) that grazed an Argentinian's outstretched. A goal kick was given, should this have been a corner? This was very subtle though. Finally there was the Argentinian goal disallowed in the closing minute of normal time, this definitely would have affected the game, it would have meant no extra time.... but no wondergoal in extra time.
That linesman must be breathing a sigh of relief that his decision didn't change the result now he's watched the replays!