It sound's as though he could possibly get away without tagging this buck ,but I have to agree with the other's that if he shot it he should tag it ,unfortunately he won't get the use of the meat . this is a tough situation ,he owed the animal a 100% attempt at taking this deer home with him and it sound's as if he didn't do that.You just can't shoot a deer and not try your best to harvest it and go back a few day's later fin him and take his horn's ,I would find this to be unethical on his part ,but maybe according to the law's of his state he might just have a loop hole .

nubo