He never said they manually triggered an alarm. He said they could very well be lying that a detector was ever used let alone registered explosives.

That would be extremely gutsy on the part of the TSA employee... I go through the pat-down dance at least once a month, and that test is always done while I'm standing there, and the pass/fail reports are quite obvious (big green/red boxes with text).

Is that dependent on the airport? I've flown as recently as two months ago, and I went through four pat-downs over the course of the trip. I never saw any green/red indicator when they tested the pat-down gloves.

Regardles, I wouldn't exactly put it past the TSA to make up a positive hit. It's not like we haven't ever had a police officer claim someone committed a traffic violation on someone based on appearance and ultimately find drugs or some other criminal behavior.

Perhaps.

In the past two months, I've had pat-downs in DCA, BWI, and PHI (my home airport, SYR, doesn't have scanners, so there's nothing to opt out of).

They all use machines similar to this one:

http://www.tsa.gov/sites/default/files/images/edt_closeup.jp...

I've never seen a failure myself (the green bar you see pops up after a few seconds), but according to a friend who has, a red bar pops up instead.