As far as I can tell it's real, it's a video from a police car. However what the full story is I don't know.
I heard from a colleague that the pensioner was stopped by the police for not wearing a seat belt after after stopping when police went to talk to him he drove off and apparently hit a policeman in the process. In such situation apparently it's normal practice to disorientate the driver by break the car's windscreen. Seems a bit far fetched to me, but why would any policemen do it knowing full well that they were being filmed?