I can understand why Clarice didn't go there. Novak is the only person who has claimed that Armitage intenionally revealed Val's identity and role in order to get them published. As such, it is open to speculation.
Ms. Feldman chose to only use items accepted as facts to lay out an indictment against Fitzferbrains. It is a damning indictment, made more powerful by avoiding anything the least bit speculative.
Besides, Novak's claim that Armitage "invited Novak in for their little chat for the express purpose of getting the column written" leads down a different road than where Clarice is going. It's a road of conspiracy and intrigue between the State Department and Wilson that will surely be investigated, but apart from the prosecutorial misconduct of Fitzpatrick.
This my take on that sordid deal: Grossman knew Wilson and the two cooked this whole thing up. Grossman, however, as a suborinate of Armitage, couldn't order Armitage to talk to Novak. So Grossman went to Powell, probably with Armitage's knowledge, for permission to spring the trap. Powell gave it his blessing, knowing that his ever loyal Armitage would serve as the cut out man. A neat little three man conspiracy (four, if you count Wilson) amongst people who will forever remain tight lipped. All of the other players--the MSM, DOJ, CIA etc. acted rather predictably.
Totally plausible. And John McCain is running around saying that Powell's opinion on detainee treatment should be given deference because of the high quality of his character. Feh!