I watched the vid again, frame by frame. It seems as though he survived because the wall broke up in transit, including the part that fell on his ankle (the corner broke off). when he first stands up, for a couple of frames he actually stands on that leg, stops and looks down at it. Now I know from hard won experience (motorcycle accident), that when a bone is broken, you don't feel it immediately. So I think that his ankle IS damaged. you'll notice that when he starts to walk away, he transfers weight to that leg, and quickly collapses. At that point the vid ends.