Correct Offsides Call in South Africa vs. Mexico

ESPN Flubs South Africa vs. Mexico Offsides Call
When everyone took a breath, it turned out the refs got the call correct.

In short, the offside rule reads as follows:
"A player is in an offside position if: he is nearer to his opponents' goal line than both the ball and the second last opponent."
Since South Africa keeper Itumeleng Khune charged off his line, trying to push away Gerrardo Torrado's corner, it left only Steven Pienaar left on the line. That meant when Khune went forward, Vela was in an offside position, regardless of the Everton man's position on the line. Just think of Pienaar becoming the de facto goalie on the play.