Definitely plead not guilty. Get a lawyer if you have to but this seems like a case where the charges should be dropped. The law wasn't designed to charge people with technicalitites but to stop the illegal transfer of deer for unlawful purposes. Whether the paperwork was correct or not, if they go to court , both father and son, I would think the court/prosecutor would reconsider their position. I would certainly plead not guilty. Forget the convenience argument, Who knows, in a couple of years a misdemeanor like this on your record could probably prohibit you from owning a gun, so why accept it if they are not guilty of an intentional crime. Officer may be facing a lot of poachers claiming the same thing. Maybe when they get down to court and the officer sees that they were speaking the truth, and both father and son are there he'd agree and recomend to the prosecutor the charges should be dropped. Talk to a lawyer. best of luck to them.