Having gotten a lot of driving in on the Clarity, I eventually realize that sometimes, (even when the HOLD function is off), the vehicle will creep forward after a complete stop. And other times, it will act as in N and roll backwards with the slope. (I think it depends on how firmly I press the brake pedal but have not confirmed).
I did happen to drop by the exact same gas station I initially reported the issue at. It has been rainy here in Southern California and I took a picture of the culprit!
I must have just so happen to have the front tires on the upward slope of that rain/water channel....