This is another one where the aircraft was never in any danger - at least, no more than it would have been with an unarmed pilot at the controls - but I am glad that the pilot was caught.
I'm a gun owner myself, but guns are one thing that I believe actually belong on the prohibited items list.
I'm also of the opinion that flight crews and airport workers should all be required to go through the same screening as the flying public when they report for work in a secure area of an airport. If the current screening regimen is too much of a burden to impose it on airport workers and flight crews, then perhaps it's too much of a burden to impose on the flying public, as well.
But x-raying a pilot's bag when he arrives at the airport to go to work? Yeah, I can get behind that.