A uniformed cop "standing in the middle of the road" pointing to a parking lot is always considered by the motoring public to be on-the job.
ANY REASONABLE PERSON WOULD BELIEVE THIS TO BE A COP DOING HIS JOB AND THAT THEY MUST STOP!!!
The "check point" is a distraction from the real issue, a uniformed cop compelling a citizen to stop under the color of law and without RAS. Prosecute that cop and any cop that engages in such activities.