Some of the evidence cited against him look like notes taken by interviewers, not direct trascriptions of what he said.
I agree. But the essential point is merely the difference between hearing/learing it first from the CIA or other independent resaerch, and hearing it first from a reporter or reporters. He told the GJ he heard it first from reporters.
Nevermind the detail diffs in the stories - Miller, Cooper and Russert had "the ssame" sort of recollection on that point - See the differences between paragraphs 32 and 33.
It just looks like Libby lied to the investigators. The truth would have done fine.