Awfully thin legs. That's too bad, Hill will be recovering for quite some time.
The tap or do not tap thing is a good question. We hear so many times about a champion never quits, you should never give up, mind over matter, etc and then someone applies those beliefs in their fight, and he's called a fool. Personally I believe the ref should stop it if there is danger of an injury (like CB Dolloway/Amir II). If a fighter refuses to tap. more power to them. If they are injured as a result, they'll have to deal with it but they'll preserve the integrity of not quitting.
I'd like to see less guys tap out, especially to strikes (GSP/Serra I), from exhaustion/frustration (Shamrock/Ortiz I), or non joint locks. If you just can't handle the pain and need to be released from a hold, I think we can all understand that.
Personally, I would never tap out in a fight, no matter what.