OK then, supposing I am mistaken, what did it have to do with? What were the limits of her testimony?
I believe that (according to Miller and her attorneys) Fitzgerald in effect agreed to not ask about anyone but Libby.
But even that might not have been the exact truth, since it is clear from Miller's subsequent remarks that after saying Libby was not her source that she was asked the further question: "then, who was your source?" To which Miller replied she couldn't remember.
I'm not saying that your wrong, btw. It might turn out that Miller did have a hand in tipping off the Holyland foundation folks. But that allegation hasn't gotten very far as far as I know.
And part of me thinks Miller showed a lot of intestinal fortitude in standing up to the NY Times and telling the truth about her source (that is, not being Libby), which cost her her career. But it might turn out that I'm wrong about that, too.