Sorry to hear about your little ‘incident’.
Sometimes police drivers make mistakes, and I do think that standards in police driving have dropped over the years. However even the most conscientious driver like me can get it wrong. I myself have occasionally had little ‘suprises’ when people suddenly loom into my conciousness whilst driving through a lack of observation. I once nearly had an accident with a rather large fire engine coming the other way answering an emergency call because I was concentrating on looking for someone who had just robbed somebody, was listening to two different radio channels, and was hoping that the motorcyclist who was following me on my way to my call would back off and stop using me as a means for him to get through the rush hour traffic.
So yes he shouldn’t have pulled out on you, but at least if he had of hit you, he would have been insured and would have known some first aid:)