As someone who used to live in the Boston metro area—Somerville, to be exact—this story surprises me not at all:

Except for my one year in Albuquerque (and, arguably, my time in Brooklyn), I have lived in snow-infested areas, and in all of these areas EXCEPT ONE, they knew how to deal with snow.
First, you plow the main streets (“snow emergency” streets in Minneapolis, e.g.), then one side of the street (even, say), then the other (yes, odd). This meant that you needed to move your car off those to-be-plowed streets, on which, after they had been plowed, you could then park your car.
There was also the general sense that, after you shoveled out your car and drove away, your slot was fair game. As someone who almost always cleared the hell out of her space, I tended to think I hope someone appreciates what a great fucking job I did clearing that spot—I didn’t want all that work going to waste.
But not in the Boston metro area, no. There, you cleaned out your spot and then you marked it: with a traffic cone, a trash barrel, a lawn chair, perhaps an old appliance (really!), and if someone took that spot, well, you were within your rights to do some damage.
And by damage I mean damage: if you only packed snow all over and around the interlopers car, that’s nothing. A broken headlight, a flat tire, a keyed side panel, and, if you were caught in person, a fistfight, yeah, these wouldn’t surprise anyone.
I should note that this utterly-fucking-nuts sensibility likely had something to do with the fact that, with the exception of the snow emergency routes, only one side of a street would be plowed (and then only eventually)*; given the difficulty of finding parking in good weather, you didn’t want to lose your claim to a spot in bad.
*I once asked why this was, and was told something about having nowhere to put all the snow. Uh huh. Montréal is a fucking island but they somehow managed to figure it out. And Fall River ain’t no Montréal—or Boston.
Still, a gun is going a bit too far; perhaps had he merely punched out a windshield, nobody woulda said nothin’ but wicked righteous.
h/t Raw Story