Perhaps if the TSA spent more time looking at the people they should do, instead of kids, retirees, cancer victims, etc., they might have spotted it?
Aye.
Thought: this was a probe, by someone, who explored the art of the possible in leaving a tool for a follow on passenger to use.
It also might be that one of the flight attendants liked to engage in exotic sexual practices that includes stun guns, and for whatever reason left it in a seat pouch for later retrieval ... I realize that is an immense stretch, but weirder things have happened ...