9/11 Panel Gets an 'F' in Observation

The 9/11 panel held another petulant press conference yesterday in which they announced that the U.S. and Congress get an 'F' in their report card, apparently because they haven't bowed to every wish of the panel. Back when the panel issued their report, they acted as though their words were being handed down from a smoking mountain on stone tablets, and they clearly haven't lost their over-developed sense of importance.

However, there seems to be one minor point that the panel missed when they assigned their grades:

There have been no terrorist attacks on U.S. soil since 2001.

I wonder how they missed that? It seems that, at the very least, that would be worth a passing grade.