That's not a fair statement. The lines of when an encounter is consensual is vague at best. It's easy to say "just walk away, if it's not consensual you'll know" but that will most probably get you killed. The tone the pig is using, the amount of pigs around, the gestures etc can all be factors in whether you are free to go.
I would wholeheartedly support a law spelling out specifics as to when a consensual encounter turns into a detainment. It should be crystal clear.
There is an easier way. More decisive.
Just declare to the cop, "No offense, officer. I know you're just doing your job. But, I do not consent to an encounter with you."
This instantly makes any continuation by the cop a non-consensual encounter.
You just bounced the ball back into his court. Now, he
must play that ball. Now, he
must have reasonable articulable suspicion (RAS) (see Terry v Ohio and subsequent cases). Or, he
must have some other exception to the warrant clause, for example, a community caretaking function, etc. Furthermore, if it later turns out he did not have RAS, he's actionable.
If you make a bit of a study of court cases about detentions, one thing starts to become clear. There have been reams of cases where the courts are sorting out whether the encounter was voluntary or not. The courts dig into minute details. BUT! The only reason they are doing that is because they have to--the detained person never said, "I don't consent to an encounter with you, officer." I have not yet seen a case--out of perhaps a few dozen--where the detained person declared "I don't consent to an encounter". Not once. Never.
I developed this tactic from a federal case I read. It didn't sink in until later when I saw the federal case quoted in a VA state case. Here is the paraphrase: Fourth Amendment case law recognizes three types of police-citizen encounters. 1. Consensual encounters. 2. Brief, minimally intrusive, involuntary encounters based on articulable facts sometimes referred to as detentions. 3. Highly intrusive custodial arrests.
The courts handed me the hint. They recognize whether an encounter is consensual.
We already express refused consent on the 5th Amendment right against self-incrimination. There is no reason you cannot do the same thing under the 4th Amendment.
During an encounter, after I politely refuse consent to the encounter itself, if the cop continues the encounter for even one more question, then I just assume I am seized. Instead of asking
whether I am free to go, I would ask, "
When will I be released from this detention, officer?"
Cops are good at dodging questions, including, "Am I being detained?" And, "Am I free to go?" Why let a cop (or anyone) keep you uncertain by dodging or otherwise not answering your question? Just take that initiative away from the cop by taking the initiative yourself. "I do not consent to an encounter with you, officer."