The post was in response to another member's new motto (I'm not going to look it up now, so forgive me if I don't get it exactly right) of "Arrest me or leave me the hell alone." If the officer is pursuing a legitimate investigation and has probable cause at that instant to make an arrest, he might very well decide to go ahead and do it. Only the cop that was playing the bully and was bluffing would be overcome by this tactic. The gravity of the offense would determine whether it was worth the time and effort required to go through with the arrest, but most of the cops I know would not readily back down just because someone got in their face.

I believe I gave some examples where there was prima facie evidence of a crime, but a brief investigation revealed that the situation was not as first suspected. This kind of thing happens all the time, and cops generally get the exculpatory information by asking questions. If you don't want to answer the questions, that's your right, but I have to look at that as indicative as a consciousness of guilt (unlike the courts, the cops don't have to operate on the foundation of a presumption of innocence). Given that a big part of the job is to find and investigate crimes and attempt to identify the people responsible for them, this is not an unreasonable course of action.