Prius owner has a meltdown
It seems that you have conjured up a rather well-developed scenario as to what might have happened in order to support your position.
However, I am sure that you would agree that you really don't know what did actually transpire, though, in fairness, that is true for all of us, apart from those who were there.
All we know is that the woman approaching the truck behaved like a wild animal, while the folks in the truck were essentially restrained in their responses.
What happened before, if anything, would dictate whether the woman was or was not justified in being upset, but that is clearly another matter or separate issue.
Perhaps things would have played out differently if she had said something like, "Could I ask you to shut down your vehicle...it's creating a lot of fumes which is disturbing to me, and is also wasting fuel and causing unnecessary pollution," or something like that. Maybe she did...but maybe she just sat there and fumed, and went to DefCon 4 right away. Again, neither of us was there.
If she initially spoke quietly and reasonably up to that point, and if the truck folks responded by inviting her to perform an anatomically impossible or at best a highly improbable act, it would then be "on them," and I would agree with the Prius crowd.
By the way, I am not a total Libertarian or whatever, as I think that jerks who insist on going down the street with their boom box cars blaring to the point that the street actually vibrates should be thinned from the gene pool.