Life is too short for dealing with idiots
I'm not sure who you are suggesting is an idiot?
I would have thought someone who wants a definitive answer to all situations, without specifying the circumstances is probably the idiot.
The law is rarely black and white and without knowing the precise circumstances, it is not possible to give you a definitive answer.
Hence why there is a huge volume of case law on what "acting in the course of his duty is" in relation to the actions of police officers.
An action that may be in the course of his duty in one case, may not be in the course of his duty in an almost identical situation.
Hence why it is for you to decide whether you are going to stop or not.