I wish this were true. But it is still deterministic. Either you are the first couple in line or you look suspicious becaue of your looks or standing next to someone who looks suspicious and you look very unsuspicious. Other than that, there is no other randomness.

You can still beat it by waiting until they are busy.

On top if it, in all the screenings they did, they missed enough things in their cursory look that if people were intentionally trying to get some objectionable items in, they wouldn't have much of a problem problem. So it is really not a deterrent.