Ulfric said he shouted him to the ground and then ran his sword through his chest, but at the same time everyone else who witnessed the event said his body disintegrates when Ulfric shouted at him. Perhaps both are true, Ulfric's shout may have inflicted a mortal wound, but Ulfric delt the final blow with his sword.
I would love a cutscene of that fight, from ulfric walking into the castle and offering to do battle, up to the part where he makes his escape


