The odd mistake would imply that most of the time they get it right. Exactly how many genuine Islamic fundamentalist terrorists have the police shot dead in the last ten years? Oh there was that one they shot by mistake last year (oh no, it was the gloves that shot him ), but he was found not guilty of anything at all.
So I ask again Joe, how many times have firearms officers got it right, and shot dead a terrorist about to commit mass murder?
The shot for shot comparison doesnt hold up. You have to ask how many suspected terrorists have been rounded up. And the services are doing very well - although it will never be well enough. And dont forget, they have to be pretty damned close to doing a terrorist act before they are rounded up - otherwise the 'human rights' kick in. To me, the mistake was misidentification - everything else was procedure.