Nobody...not even cops...can be allowed to break the law.If,by chance,that cop committed a crime in questioning that person where he did and when he did then prosecution should be contemplated.If,OTOH,what he did wasn't a crime then that lawyer,IMO,can go bleep herself.It ain't rocket science.
“If,by chance,that cop committed a crime .... then prosecution should be contemplated.”
Why should prosecution of a criminal under your hypothetical be merely contemplated? Why shouldn’t prosecution then ensue?
As you say, this is not rocket science. One would think the most important criminals to get off the street are those with a badge and gun. They are certainly the most dangerous criminals to the general public.