Bush apologist, the Wall Street Journal's James Taranto, blames the Plame-Wilson investigation:
Of course, much as this [investigation] seemed like a sitcom, it had consequences in real life. Because Armitage [source of leak] did not come clean right away, many people suffered:
... Innocent White House officials were distracted from serving the country in order to participate in the investigation, which was in full swing a year ago when Hurricane Katrina struck.
UPDATE: The excuse is seconded by the National Review's Cliff May.