Originally Posted by Bart

I already answered this question. I suggest you ask to speak with a supervisor if you are not allowed to observe your bag being physically inspected in a public area screening pod. If the supervisor doesn't answer your questions to your satisfaction, ask for an airline ground security coordinator (GSC) who acts as the liaison between the airlines and TSA. If still unsatisfied, fill out a complaint form and address it to the airport FSD.

You have the power to ensure TSA screeners follow correct procedure. Use it.