Yeah, y'all made a mistake by not checking the deer, but I have forgotten to do it the day of and did it the next day or day after when I remembered (in VA, you notch your "tag" on your license, then are required to check the game either by phone or web within 24 hours). An honest mistake, especially when you've got a lot going on, have a carcass to skin, quarter and butcher, and have wife and kids wanting your attention when you get home. The thing is, you can't prove good intentions, so although the $50 fine is a PITA, it's not completely unreasonable.
I think it is interesting that the officer told your friend after that fact that he basically made a mistake by letting him in the house. I know your friend wanted to cooperate, but he's also got to understand that the LEO has a duty to cooperate with his rights. They are trained to undermine your rights though, to word things in a way that make you think you don't have a right to say no, and if you do, you must have something to hide, etc...it goes on from there.
I hope your friend gets his stuff back, but IMO this was a painful lesson in what it means to know your rights AND TO USE THEM. Sounds like your friend bent right on over and took one up the yin-yang from the State.