I've had the chance to watch it a few times now, and i'm convinced it was just a lucky goal. If anything, maybe it should be an own goal, credited to the French keeper, Mickael Landreau. If he had a stronger hand, that shot would have sailed over the cross bar.
Thought, not to take anything away from McFadden, it was a brilliant strike, the turn, touch and shot. Watch it again for yourselves.