More crappy refereeing.
Giovani Dos Santos scored from a cross from the right which should have put Mexico ahead, but the linesman wrongly ruled it out for offside.
A short while later Dos Santos should have had another goal, but again it was disallowed. He was offside when the corner was flicked on to him, but it came from a Cameroon player, not a Mexican one.

It rained a good bit during the game – so maybe the rain got in the linesman’s eyes.