I still don't really understand the finish. He's scored with his instep as the ball travels across (or through??) the outside of his boot. He hasn't flicked his foot around it to get the angle, his leg isn't travelling upwards to meet the cross, his body position is always facing straight at the goal and not pivoting towards or from the incoming ball.
It's a bit like string theory or internal workings of a woman - I want to appreciate it, but every time I try I just get confused instead. A wizard did it; that's my conclusion.