In a paste-up investigation with a crime that had already been solved? There was no need to ever interview Libby in the first place. If an aggressive prosecutor gets after "Choldt' he will get him on something also. You seem to be stuck on the infraction, not the 'conspiracy'. I threaten Choldt with molesting his children 20 years ago and hope he will spill all the info I really want to destroy someone else.
Well, you likely know this... sorry to be argumentative.
From the investigator's point, 1) it hadn't been solved, and 2) leaking is not a "second and subsequent leakers get a pass" crime.
I totally agree, not only was there no need to query Libby, there was no justification for investigation. Not on a "who leaked" reason, but on a no crime if everybody leaked basis. Fitzgerald didn;t want to probe that end first (was Plame covert), he went frpom the other end for political reasons.
This the nature of law. The players and the system are dishonest. Lesson? Break the law. It's all about force, not about rules.