I've encountered players that sound a whole lot like this. For whatever reason, there's a certain type of player, that when presented with a figure of authority, cannot help but insult and abuse them. It's related to the Instigator player type - they like to do stuff just to make stuff happen, good or bad. But I think it's also a way at pushing at the boundaries of the game, like trying to find the limit to the map in a videogame. They want to see just how much they can push at the world without it breaking.
This is a particular pet peeve of mine and one I too often encounter. I tend to place characters into the following broad categories.
- Instigators: Players who just like to stir the pot and sow chaos.
- The Anarchist: Players with a pathological dislike of any character in a game with some authority over their PC (it's not like they can tell their boss to go #%%# himself in real life).
- The Unliable: Players who think the role playing aspects don't really matter, believing the plot will plod along as planned regardless of their character's behavior (kind of like how it does in video games).