Road outrage

I am driving a friend to the airport.
In Georgetown, the streets are filled with people, a different feel from the rest of the city which has been deserted in this Thanksgiving weekend. We're waiting at a red light on M street, before crossing to Virginia. The car in front of us wants to turn left. Its blinkers are on. Then, without any apparent reason, it moves to turn as the light is still red and cars are passing by in the others directions. I cannot believe my eyes: the light didn't just become red, it is not about to turn green. It is red. Plain and simple. The car finally sneaks between upcoming cars and makes its turn.
My friend, a French Canadian living in the states for a long time and married to an American, is just laughing at my outrage. Where are those drivers coming from??