Harpy, and what happens when something does kick off on board when all the arses out there are making these crass remarks ?? Security are hardly likely to say "Doh ! Hey guys he wasn't kidding, ****** !"
Yes ok, but when talking of sense of proportions, you don't mess around at airport security, full stop. May seem draconian, but anything less is irresponsible to the remaining pax and crew.
If I was behind this arse or persons like him at security, I wouldn't want to sit next to that type of person on board. His attitude at security would typify him as a complete wan*er anyway. And if as you suggest he was getting arsey and frustrated about having his penknife confiscated in the current climate, what type of idiot are we dealing with here ???