While I would not condone the TV crew's attempt at passing a fake bomb, their actions were most likely prompted by leaked classified reports of TSA's repeated failures at detecting bombs, weapons, and explosives during internal testing just last year.
What's more, the agency's own inspector's office has been repeatedly blocked from receiving information that would assist in evaluating the troubled agency. The agency has also been criticized for failing to adapt to threats, leaving expensive programs in place that have little correlation to calculated risk.