Sure a deer can leave on three legs, but that broken leg can get infected and it could die a long, slow and painful death. Plus from the way the original poster described it, the injuries sounded worse then just a broken leg. Either way he humanely dispatched the deer and he is using the meat so what's the problem? In my opinion he likely did that poor buck a favor. I would kill a badly injured deer without remorse regardless of the season or the black letter law, but that's just my two cents.