I am quite sure that an agency would not differentiate between something seen as a viable device or a device which is benign. The procedures and actions following recognition of a potential threat must be identical.
Post discovery, discussion regarding the intent of the crew becomes academic since it was obviously their intention to deceive at the outset. If it were any individual passenger attempting the same subterfuge, one's feet would not touch the floor.
Embarrassment of a government agency plays no part here, when the crew set out, they very effectively labelled themselves as a legitimate target. The officials are armed and fully aware of potential life threatening encounters. The crew were fortunate not to be taken down.
A period of incarceration for all parties from the top down should be de facto for this idiotic attempt at getting ratings.