The LE individual you consulted with is very knowledgeable, but after almost 20 years in LE myself, before retiring, I made many arrests for misd violations. They are considered a violation of law. Though a misd can be classified as either unclassified, or an A misd, I have been involved with many.
A good example would be driving with a suspended license. That's a traffic misd, but lets not split hairs here. If you want to consider someone a criminal for any misd then I suggest you never invite them to your home for dinner, or have any association with them. Usually violations with guns that are considered taboo are those such as reckless endangerment where the safety of others are concerned.
If Nugent were a resident here he'd definately lose his license, but then again I'm sure you'd be happy if that happened. Here they'll take your guns for arguing with your wife. I don't think he'll have his guns taken away and if they don't take them then apparently they don't consider what he did criminal enough.
What happened to Nugent would be like you shopping at Win Dixie and mistakenly stuck 3 sodas in your shopping bag, when they were 2 for the price of 1 and walked out the store and got bagged for shoplifting. That's a misd and you committed a criminal act. Fagedaboudit, it was just a bear.