I agree that "hooligans" are a problem, but accidents happen, even to careful, conservative acting non-hooligans. I suppose it would be pretty rare, but if someone is hurt in a bike-caused accident and they sue the bike rider/owner for $100,000 in damages, which is probably not a lot for a head or back injury, lawyers and insurance companies and their lawyers are going to be involved. They won't miss the fact that the bike was a class 2 where only class 1s were allowed. That won't be good for the bike rider, even if he wasn't at fault.
That little scenario is kind of like the campfire story about the guy with hooks for hands who escaped from the nearby prison. It's highly unlikely and you can probably go a few lifetimes without it happening to you, but people buy insurance not just because things happen to them but because they might.
Put another way, you can get away with riding a class 100 bike as long as you get away with it. No consequences and nothing but fun until something goes wrong.
TT