[OT] Pedestrian on freeway points gun at you while you are driving to work: what do you do?

The local Toronto newscast had a story about a guy standing on the 401 - a major highway running through Toronto (and all of southern Ontario) - during the morning commute pointing a gun at people on their way to work. It's still pitch black out so visibility is bad.
https://www.youtube.com/watch?v=4C0ntDsmra4 [first story in this newscast]
I'm curious to know what YOU would do in that situation.
Honestly, my first thought is that if I experienced that, I'd assume he was a bad guy of some kind and I'd worry for my own safety and those of others. I'd be strongly tempted to run him over in self-defence. In this case, I'd turn out to be right: he IS a bad guy. I don't know whether that would get me off a criminal charge of injuring or killing the guy though. Or would the police decide it was his own damn fault for trying to cross a major highway in the dark and not lay charges? Or would they make an example of me because I injured/killed a black guy?
And what if he was actually a plainclothes cop who was looking for a lift or even to commandeer my vehicle to chase down a bad guy? Or a guy with major mental issues or high on drugs carrying a fake gun or even just something that I mistook for a gun in the darkness?
I don't suppose you can ever really know what you'd do on the spur of the moment if something unexpected and potentially dangerous happened.
I'm reminded of something that actually happened to me 20 odd years back. I was just leaving work after a late shift and walking back to my car. I was downtown on a major street that was one way with three or four lanes of traffic but there was hardly a soul around. I was parked on the opposite side of that street and I'm a chronic jay-walker so I just crossed close to my car in the middle of the block. There was a car coming toward me in the lane closest to my car and I crossed in front of it but with ample room to spare. It was a rare windless night and as the driver passed, he had his window open and said something, apparently to me, about it not being smart to jay-walk. I muttered something that I thought was under my breath about being perfectly capable of crossing the street safely. I never would have imagined he could hear that but it was windless and very quiet out and he reacted to my words with a bit of a start and words to his passenger that I could not make out. I didn't think much of it but I noticed that he turned left on the next corner past my car and parked, and two guys got out of the car. They started walking toward me in a way that suggested purpose. I somehow realized - or maybe just feared - that they were coming back to have words with me. I have no fighting skills and I didn't fancy the two-to-one odds in any case so I got into the car and fired it up. They stepped into the road as if to block me. I didn't even bother to put my seat belt on - and I ALWAYS wear my seat belt - and just started driving. I was ready to run those guys over and maybe they could sense that because they got out of the road and I didn't have to hurt them.
So maybe I *do* know what I'd do if the situation in the video happened to me....
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Rhino