That just sucks for your friend.
See, I'm thinking that if a sportsman comes clean like that, a reasonable GM would find a way to not penalize the hunter but not reward him either.
The GM could have given the guy a pass, but made him leave the deer lay.
But then as a GM, what do you do? If word gets around you're "flexible", you'll be dealing with more BS calls, as if you didn't have enough already.
That just sux.