If it's on its feet it's fair game. I have had to give up deer because of this and have taken deer because of this. It is the most straight forward approach to this issue. Everyone will argue over what is a killing shot and it can get real messy (as you have seen).

My advise is to get a littl bone with the next shot and put it down. I hunt in a very populatd area and to avoid this issue I make sure (if possible) to break them down with the first shot.