I recently discovered that the TSA will pull you aside and inform you that they have to give you a full pat down for failing to empty everything out of your pants pockets before going through the scanner. I had to go through this procedure because I had failed to remove two folded up paper towels from my pants pocket. I often use a paper towel as a substitute for a handkerchief.
I am wondering if I had refused the pat down and had instructed them to return my belongings because I had decided at that moment to travel to my destination via an alternate means such as via a car or bus, would they still have the authority to pat me down?