SheepDog4Life
Natural Gray Man
At this point, the encounter is still consensual. "No, thank you." is an appropriate, acceptable, and lawful response. Failing to comply with a presumed-consensual encounter is not RAS, much less PC, of any unlawful behavior or action.
If I were a betting man, I would at least wager a cup of coffee that any existing precedent case law, SCOTUS or otherwise, states the opposite of what you do here. Unless and until the police officer escalates the encounter from consensual to a Terry stop, you are free to avoid the encounter, and doing so is not evidence constitution RAS/PC.
Splitting hairs... running evading would escalate... saying "No thank, you" and continuing to go about your business as you were is fine until he "orders" you to stop.
Too busy to look it up, but pretty sure the SCOTUS case, not Terry, was the cops said "hey, we'd like to talk to you" and the suspect ran. This is that.
Any part of what the cop says sounds like "hold it right there", or he remembers saying it even if he didn't, and you're likely in Terry-land.
Betting he doesn't have RAS is not a good bet.