Whenever I encounter some dipwad on the highway being hyper-agressive and just generally a dangerous a-hole, I simply let them go by, knowing some day, some where, they'll eventually run across someone a lot better equipped to instruct them in the error of their ways.
I'm not quite sure about the legitimacy of this. The whole ending is very surreal, and suspiciously well-orchestrated. Not saying it is a hoax, just that I wouldn't be surprised if it turned out to be. The accents are pretty obviously Canadian, so I can't say what their laws would make of it. Over here, the guy in the car would be completely in his rights to pull a gun on someone threatening him with a baseball bat. Indeed, in a few states he'd be well within his rights to shoot the guy dead. Taking the camera away from them is probably theft of some sort, but no jury in the world would convict them.