Further to the issue of the Libby defense, I'd like to point out that this is another tried and true example of how blue collar criminal defendants are treated differently from white collar criminal defendants.
Consider the typical blue collar criminal case where evidence is circumstantial. When have you ever heard of a blue-collar case in which the defense has been permitted wide latitude to rebut evidence of intent with third-party testimony of what a busy man the defendant is? When have you ever heard of a blue-collar case in which the defense is allowed to rebut evidence of intent with the argument that what the defendant is alleged to have done is stupid and no one would be stupid enough to do what the defendant is alleged to have done? The prosecutor's rejoinder to those arguments on closing is that the criminals we tend to catch are the stupid ones; the really smart ones get away.
Here, Libby's lawyers argue that a busy man like Scooter, who holds down "the equivalent of two full-time jobs" and whose head is filled with the important information of state has a reputation as a brilliant but forgetful man, so it is entirely conceivable that he simply forgot the truth when he testified both to the grand jury and gave an interview to an FBI agent. I can accept the idea that Scooter -- far busier than I am with a far more demanding job than I have -- might not remember all of the details of a particular event that took place weeks or months previously. Heck, I often forget things that happened two minutes ago on the way from the kitchen into the bathroom. But in order for me to believe that Scooter's brain is so full of something that the something pushed out the memory of who outed Valerie Plame, I think that I would need to know what else was in his head, and the defense certainly tried to offer evidence of that.Imagine how your typical judge would deal with the issue of a blue-collar defendant seeking to put his friends and family on the stand to testify about how busy and distracted the defendant was at the time that he allegedly formed the conspiracy/bought gun/entered the convenience store. If your answer was, "inadmissible", then you win.