I know a bit about police aviation in England so I can answer some of your questions.
What I would be most interested to read are fellow rotorheads perceptions about what they think the police aircraft ought to be doing especially with regard to cost effectiveness.
It was clear from the video that the injuries were bad, remeber that you were on scene a long time before the heli. It also clearly states in the Police Aircraft Operations Manual that a CASEVAC is a flight, the purpose of which, is to give immediate assistance to a sick or injured person, in life threatening circumstances. The police observer who turned up and asked the question "Will this person die if they do not go in the helicopter?" was IMHO completely correct in his actions. Well done.
I did not see the whole programme so can not comment on the rest.
What I did see was a police air support unit going out catching criminals and preventing crimes from being committed. As far as I am concerned, thats what they should be doing.