With Libby handling heavy duties in the White House, there is no reason for his memory to be expected to be better than that of others about something like this -- much less to convict him of perjury.
As for the pay-back conspiracy theory of a Bush administration-inspired leak because of Wilson's opposition to the Iraq war, Richard Armitage was not an Iraq war hawk and columnist Robert Novak opposed the war. They had no reason to discredit Wilson.
Even the term "leak" is misleading. In the course of a discussion, Novak simply asked Armitage why someone with no expertise like Joe Wilson had been sent to Niger in the first place -- and Armitage's answer was that he was sent at the suggestion of his wife, who worked at the C.I.A.
Novak's column was not about that fact but mentioned it in passing. From this the liberal media went ballistic with conspiracy theories that we now know were totally false.
A man's life has been ruined because his memories differed from that of others -- whose memories also differed among themselves -- and media liberals are exulting as if their conspiracy theories had been vindicated.
More important, how are we to expect highly qualified people, with far better options than a government job, to risk being put through the Washington meatgrinder because of politics, media hype and special prosecutors who can create crimes in the course of an investigation, when there was none to begin with?