It seems to me that if I was an officer, I'd follow the law to the letter, and in such cases as it (the law) doesn't sit well in application to a certain situation like this one, I would do my best to speak on behalf of the arrested party.
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Hard one, I know, as in this case the man brought on his own strife by actually breaking the law, even if not in spirit.
The system would function a lot worse, and more injustice would occur, in a zero tolerance world. If you start out with the supposition that the law is designed to discourage bad behavior, rather than merely to punish, the goal frequently can be accomplished without the need for enforcement action. Once an officer makes a decision to act or not act, s/he owns the decision, so it behooves the officer to examine the issue in good faith and have a really good rationale either way.
"Don't believe everything you see on the Internet" - Abraham Lincoln
