Re: the offsides call, the rule is that you cannot be even or beyond the second to last opponent when the ball is played forward. It's usually the last defender as the goalie is back at the goal line. In this case, the offsides occurred, not off the corner, but when the player receiving the corner kicked it goalward. At the moment he played it forward, the goalie had come out of goal and there was only one defender [the one on the goal line] closer to the goal line than the last offender to touch it.
Meh: that's what I get for forgetting that I was on page 3, not 4. Already answered. I'll leave it up as the video lays it out clearer than a still.