Legally, HERE, the last bullet into a live animal, is the one that killed it, even if it is a hoof hit, while the first, lung hit, your's, actually killed the animal. Many guys here have lost their licences and guns, for being the last one to put a bullet into a moose and not being the one to cancel the tag. The game branch used to spot for this, using powerful spotting scopes, over game runs and logging slashes, from up to 1,000 yards away- they always get convictions - go figure. The minimum is $1,000 fine and loss of gun and/or vehicle + 5 years loss of licence. No wonder there is so much poaching going on here. No wonder some hunters can gut a bull moose in 10 min. or less.
Legally, in most areas, I think, it is the other hunter's deer- which is why guys do it, even though they may know it has been shot already. This is what the hunting rags say, anyway.
: Next time, in those tight hunting conditions, drop the deer on the spot or face the possibility of this secnario happening to you.