To pick out one player at fault defending that set piece is bollocks. It is a good position and difficult to defend that one when the cross is as accurate as that. Our defending of set pieces in general is comic yes, but it mirrors the fact that BR has never felt the heat inside the box during a top match. No one covering the post in example. With only the goalie on the line the net is wide open for anyone who manage to flick it toward the goal. And the way Arsenal plays, with double up and sometimes tripple up in wide positions, with the ball moving rapidly and accuratly it is not comic defending in the moment that set them up. It is a weak defesive set up as a team allowing them to get in those positions. They did it all match, and the one he scored from was no different than the few Reina saved. it is a big difference on Comic defending with personals mistakes and weak defensive setup.