While ultimately flawed, this thread does bring one interesting point to mind.

Katrina was by all accounts catastrophic, both in terms of monetary loss, and loss of life. You could therefore argue that the net effect was that of a category five. Therefore, what does the NHC do in the face of impending catastrophe from a weakening storm? Downgrade said storm resulting in an equally lesser regard from the public? Now you see the dilemma forecasters face with each decision in the hours prior to landfall.

The facts are still the facts however, as Clark pointed out.