"In 2000, Independent Counsel Robert Ray concluded that then-first lady Hillary Clinton had provided materially false testimony in the Travelgate investigation.
Mr. Ray declined to indict, however - explaining that he could not prove that Mrs. Clinton's false statements were intentional."
What you have with Libby is the charge that he lied when he told a grand jury he first heard about Plame from a reporter, not Cheney. It's not even clear that it was false, or if it was false, it sure isn't clear it was intentional. But he's not the hero of the Democrats/media so he doesn't get the benefit of the doubt.