He strikes a nuanced position:

If there’s a bigger buffoon or more gutless weasel in the intelligence world than George Tenet, he’s being hidden in a black ops prison on Guantanamo Bay.
Tenet, a poster child for “The Power Of Positive Brown-Nosing,” has hit a new low, even for Washington. Having worked his way up the political ladder by leaving no back unslapped, on the way down he’s leaving no back unstabbed.
George Tenet is the Barney Fife of the spy world. Every bad guy got away, and he never took his bullet out of his pocket.
Screwing up the pre-Iraq war intelligence alone makes him a failure. Utterly missing the 9/11 attacks and having not a single CIA asset in the Taliban or al-Qaeda at the time earns him “Worst CIA Chief Ever.”
But Tenet’s incompetence overshadows even these “accomplishments.”