"Inadvertently" was the operative term. It means that you may have but not intended to but somewhat did. Opening the window can be interpretted as taunting him.

Take it easy, man. There's a lot of good intentions turning to doubt.

For instance there was this joker earlier in white plains from coming Green Meadows who insisted to drive in the middle of the road taking two lanes.

When I tried to overtake him he slams on the brakes because of those pleasant humps, I honk my horn.

I finally maneuver in front of him to take a left towards EDSA and the son of a bitch tries to cut me off. and veers off to the right towards White Plains, stopping at the intersection and giving me the finger.

He probably thought that when I assumed my lane that I "cut" him off. So go figure.

I don't know really, but how much gall does one have to be a road hog and how much intelligence does it really take to figure out that the raised middle finger really doesn't hurt anyone?