I learned a long time ago to approach downed game from behind with my rifle loaded and at the ready, when actually at the animal I touch the OPEN eye with the muzzle to check reaction..........no reaction, no problem. Although deer can be somewhat injurious in this situation it gets a lot hairier with grizzly, cape buff, lion and the like. Yes it is unfortunate for the deer, but it does happen. Best case another hunter was able to harvest it, worst case it was eaten by wolves and/or coyotes, which would have been his final demise regardless.