Man on bike vs. traffic

On the highway on my way to psychiatry at Westchester hospital this morning, I saw a man on a professional racing bicycle riding furiously amongst the traffic. Was he riding furiously because he got onto the highway inadvertently and was in full scale panic mode because he couldn't get off? Or was he training for the next tour de France? Who knows. In any case...what happened next was pretty awesome in my (humble) opinion. As he was riding along on his merry way, an SUV, perhaps assuming it had the right of way (SUVs these days!), tried to cut him off and switch lanes. Without pause, the man on the bicycle held aloft his hand and struck the side of the SUV four times (yes, I was watching eagerly and counted). Sorry, buddy, I got this lane. I mean, I know you're in a vehicle that probably weighs about 30 times more than I do...and I'm just a guy on a bike right? But, come on now. I got this.
Which made me think - what sort of person thinks that this is acceptable behavior? What was going on in his mind? Does he have a mind? Etc. Pretty interesing. Especially now that I'm on psychiatry...food for thought, I tells ya. Food for thought.