Generally speaking, an alert by a dog gives the officer PC to search. But, the officer cannot, independent of any other facts detain you just to have the dog search your vehicle. So, if you get stopped for a simple traffic violation the officer cannot legally detain you longer than it normally takes to complete the encounter just to have the dog sniff your vehicle.
As for the false alerting, yes dogs do false alert. Sometimes they do so innocently, sometimes through cues (purposeful or not) from the handler. Remember, the dog wants to please the handler so it's very easy to influence the dogs behavior through subtle (again, conscious or unconscious) cues from the handler.
First, I said in my post that the officer "states that he has
reasonable suspicion" that there are drugs in the vehicle. This would give him cause to detain you until the dogs could be brought to the scene.
Second, I didn't attempt to place any blame on the dog. Dogs should be held blameless because, well, they're
dogs.
Third, I set forth a specific scenario for this poll, an officer
illegally detains you, lies to you and arrests you. Whether they're "supposed to" or not is irrelevant to this discussion. They obviously
can and
do detain and arrest people illegally, and they get away with it. The object of the poll is to find out what, if anything, you would do about it once the incident has occurred, not to incur a debate as to the legality of the search, the conditions of which will vary from state to state in any case and is, again, irrelevant. Nor am I attempting cast all police officers in the same light, these types of things are generally committed by a small percentage of LEO's. Most of them do their best to do the job right, within the limitations set forth in the law.
Is there anything else you require clarification on?