Road rage and watermelons?!

So, I have to say besides being yelled at once by a driver for putting on my blinker when I shouldn't have, I've been pleasantly surprised in the fairly courteous way people drive here. Typically, someone will eventually let you in if you signal. However, this was not the case yesterday afternoon driving around with my real estate agent. She was trying to get over into the left hand turning lane from the right lane and had her blinker on for a while. She gunned it to get over (and later tells me the car was 2 car lengths back so she didn't feel that she cut him off too badly, if at all). The car, which she may or may not have cut off, pulls up right beside me on the passenger side and screams at Leslie and says, What are you doing? She says sorry. He says I have kids in the car. Leslie says sorry again. The passenger in the front seat throws a watermelon across the driver and it lands splat, at my window!! I jump and the guy tears off. We are both shaken up and marvel at what just happened. What anger! Nice lesson to teach your kids, dude. And what a waste of a perfectly good watermelon. Have you ever heard of such a thing? The splattered fruit was all over the car, on the top and the windshield as well. Leslie then tells me that I'll notice drivers in Seattle are angry. I have noticed how centered everyone is about traffic but this is just odd! And a poll back in April or May said for cities, Seattle had some of the most friendly drivers. Apparently that poll did not take into account this super angry guy!