I'm probably not going to be much help here. I feel for your friend espically if he's a good guy but I'm a staunch advocate for knowing the law and abiding by it. IMO ignorance is not an excuse espically if you get a law book when you get your license.
This quote:
To me this is the equivalent of keeping a walleye that is 14" long when the size limit is 15".
Shows me you may have little respect for the law. Keeping a short fish is exactly like shooting a deer out of season. It's illegal and "bending" the rules for yourself is exactly like
Breaking the law. Call me holier then thou (cause I'm sure it'll come up, it always dose) but I read, know and follow the laws in the states I hunt. If I some day decide to stray from this position then I expect to get the book thrown at me. JMO.
My best suggestion for your friend is to obtain an attourney and try to plead to a lesser charge and in the future take the time to read and know the laws.