The car has 2 drive modes: "D" and "L". The "D" mode mimics an automatic ICE car--it creeps forward when one lets off the brake, and coasts for a long time when one lets off the accelerator. I always drive the car in "L" mode, which is the aggressive regenerative braking mode. When I let off the gas it slows to a stop quickly (assuming the battery is not near full charge). And it does not creep when I release the brake.
But there is one bizarre exception: If I power on the car and put it in "L" mode, but I haven't yet fastened my seat belt, the car will creep forward when I let off the brake, just like in D. This has caught me off guard a few times, but I've always caught it and hit the brakes before the car rolled into my garage door or a car parked in front of me.
I once brought it up on /r/BoltEV, and someone claiming to be a Chevrolet engineer told me this behavior was by design, but had no good justification for it.