FYI, "misattribution" is a common, normal memory defect and is not perjury, lying and so forth.
The Judge in this case denied him an expert witness to testify on "misattribution" (DR. Bjork UCLA); this action by the judge denied Libby a chance to clear his name and resulted in the conviction.
It may not have been a misattribution. It's Timmy's word against Libby's, and Timmy (and NBC) knowingly (and with Fitzfong's knowledge) submitted a false affidavit and perjured himself in his testimony. Let's see, who to believe...