I was wondering just what could ding Hagrid up that badly. Part of why he is so lacking in the common-sense department, I believe, is that he's big and strong enough that very little can hurt him. He also does know his stuff about beasties, which is another reason I want to keep him around and available; on The Day, hippogriffs, thestrals, and dragons will be useful, just like the Veelas and house-elves will when I figure out how to get them on my side. Nothing like a faceful of dragon breath to make the other side see how reasonable it is that I be put in charge of everything, I always say.