Todd, I don't condemn you for your doeful mercy. Most ethical people would do the same. I was merely pointing out the potential legalities. Quite possibly, a Conservation Officer would have given verbal permission to dispatch the animal, if convinced that the probability of survival was slim. And that it would only lay and suffer until the final outcome.
I, myself shot a legal(4pts on one side) Missouri buck last year. One of the guides had hit it and told me about it at breakfast. We went to check its condition and found it to have 3 broken legs. It could only try and flop away from us. It was a pitiful sight, so I dispatched it. I could probably have gotten a tag for it from our DNR, but still had my Gun Buck tag anyway. The meat wasn't damaged, only broken legs. He made some excellent jerky, burger, and tenderloin steaks.