We relinquish a number of otherwise protective liberties when we elect to operate a motor vehicle on a public roadway.
Stepping out of a vehicle is not likely to produce any evidence that might incriminate you. That noted, it's as legally required (if the officer requests) as being required to show your operator's license, your proof of insurance and - depending on circumstances - papers identifying the owner of the vehicle.
When we receive our driver's licenses, we implicitly and preemptively consent to a short list of 'demands' that might be made by a police officer.
Showing the above information are three examples. Agreeing to participate in a 'field sobriety test' is another and/or submitting to a breathalyzer exam.
We are always free to NOT consent to any of the above at the point of a legal traffic stop, but there are preemptive penalties established for doing so. Suspension of license; possible arrest for "suspicion of DUI"; possible arrest for "failure to obey a lawful order" etc
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Returning to the incident that led this Thread topic - the man was not operating a motor vehicle, so his level of cooperation is almost 100% voluntary provided the officer has no Reasonable or Probable Cause to believe he is otherwise engaged in a criminal or illegal action.
Clearly, this particular incident was clusterfucked in several ways. The guy saying "I don't live here" MIGHT (dubious...but might) give officer reasonable cause to believe he is trespassing on someone else's private property.
But the appropriate response in such a case would be to ask for identification and/or to reiterate the question of "Do you live here? Because if you don't live here, you might be guilty of trespassing."
The response is certainly not to physically accost the guy and wrestle him to the ground for the purpose of - at least - a temporary arrest.
When asked the first question and then even when asked again, the guy most certainly retains the right to remain silent. And it is then in the officer's court to decide if he (the cop) has Reasonable Cause to believe the guy is committing a crime (trespassing).
Given the info at hand (thanks to the video evidence), it would have been extremely unlikely that he could have made such a call had the guy simply remained silent.
Unfortunately, the whole incident went awry the moment the officer began proceeding from the flawed stance of "You should not be videotaping me. Turn off your camera"