Just curious, what makes a former TSA executive an expert on Constitutional law?
Well he's had 25 years experience in violating constitutional rights, so I'd say he knows it when he sees it...
Prior to joining TSA, McGowan worked for a Fortune 500 company in the area of network protection. He also was a Richardson, Texas police officer for 25 years.
Unless you are searched anyway after you decline to take the plane and state that you are leaving, which should end their jurisdiction (or whatever the term is) over you.