It's interesting that the occupiers said the people in the car were drive-by shooters, and they rammed the barricade.

However, it looks like the windows were rolled up, and broken. and that there are bullet holes in both the front and back of the car.

Sounds more like the car was stopped, a crowd gathered around the car. People started banging on the car, for whatever reason. The driver tried to drive away, and was shot, because they were driving through people actively hitting the car. The car came to a rest after striking the barricade. The people in the car were dragged out.

Also telling is that no video was posted about the event, yet I believe there is.