As I see it there are 2 seperate issues here.

The first is the idiotic FAA rules, remember these are the idiots that decided to allow knives(blade less than 4 inches) and box cutters on plane in the first place.
Jane Garvey must be smoking and inhailing.
Banning nail clippers and nail files is plain silly, but what do you expect from the FAA? Brilliance, not likely.

The 2nd issue is the behavior of the pilot. For heaven sake, we just had 6000+ people killed less than 3 weeks ago, due in large part(ok this is my opinion not fact) to poor airport security. The rules have been posted clearly, they are on the FAA website among other places. The rules is pretty clear:

"No knives or cutting instruments of any size or material will be allowed in the aircraft cabin"

Since a nail clipper's purpose is to cut fingernails, it is banned.

The pilot should have known the rules, no reason for an outburst.