Why do you need to classify him at all?
He's doing his own thing, and that's okay, too.
Japanese hornets are nothing to laugh at. They are way bigger than normal hornets and very aggressive. Hornet/Wasp spray doesn't hurt them at all, it just pisses them off and they get more aggressive. We can't have the porch light on in the summer because they congregate around it and we have to enter through a different door.
That doesn't mean "WAIT! YOU STILL CAN'T GO OUTSIDE!" at all. You just have to be aware of your surroundings, like always. It's like "fire ants" - it doesn't mean you can't go outside, you just have to be aware.
I don't know if their sting will affect people who are allergic to bees the same way. Haven't thought about that.