the magistrate can only do what the laws allow them, the legal process is a bitch and you cant make decisions based on gut feelings, you have to follow the letter of the law and if the accuses has a good lawyer then there is only so much you can do in certain sittuations.....
where as a cop follows there gut feelings, they see a skyline and there gut feeling is that they can defect it easily and you have no legal representation to defend yourself as the laws have been molested to the point where a cop can defect a brand new car