Can't help but think those drivers who weren't directly involved in the robbery, had been robbed before; and are feeling especially vindictive about the situation.

That's the only explanation I can come up with why a stranger would incur some dramatic front end damage to their vehicle. "I may not get the sob that robbed me, but I will hit this sob so hard, that the sob in my memory, feels it".

Vengeance is indeed a dish best served cold.