It's just so stupid. It may sound weird but the reason it pissed me off so much was an immediate reaction to being bummed out. I would never do anything like that to another bike rider that is just riding along minding his/her business. 98% of the time I say hi to a roadie, I get a dirty look. The funniest thing is that I can most likely outride the majority of spandex superheroes around here.
Nagrom is right, I should have clotheslined the mother****er and taught him a thing or two.