?

The question mark.

eriposte at Left Coaster points to this part of Judy's story...

Soon afterward Mr. Libby raised the subject of Mr. Wilson's wife for the first time. I wrote in my notes, inside parentheses, "Wife works in bureau?" I told Mr. Fitzgerald that I believed this was the first time I had been told that Mr. Wilson's wife might work for the C.I.A. The prosecutor asked me whether the word "bureau" might not mean the Federal Bureau of Investigation. Yes, I told him, normally. But Mr. Libby had been discussing the C.I.A., and therefore my impression was that he had been speaking about a particular bureau within the agency that dealt with the spread of nuclear, biological and chemical weapons. As to the question mark, I said I wasn't sure what it meant. Maybe it meant I found the statement interesting. Maybe Mr. Libby was not certain whether Mr. Wilson's wife actually worked there.

eriposte says this...
In my view, the most important aspect of this sentence is the question mark at the end. If there had been NO question mark, then we could not have eliminated the possibility that Miller knew - prior to this conversation- that Wilson's wife worked at the CIA . But since the question mark exists, it may be reasonable to conclude that the information was new to her at that time.
Yet, Miller's comment at the end that she wasn't sure why she had the question mark is rather incredulous.

Perhaps this is what eriposte is driving at. I am not sure. But I think it could also be reasonable to conclude the question mark was there because it CONFLICTED with what Judy had known from another previous source rather than something new to her. It makes little sense to put a question mark after a statement of fact from Libby unless you thought or knew it to be wrong. Libby uses the word Bureau. But if Judy knew it was CIA from another source, then she may put a question mark there as her way of noting a question of her own, as to whether Libby didn't know it was the CIA or her other source had been wrong. In that case the question mark was a way of noting to herself that something was amiss. Something was telling her to question this particular statement from Libby. Of course a caveat is unless she had question marks after all of Libby's statements of fact or she used them as needed to signal something to check further. But then why not just admit to the Grand Jury that this is her usual way of taking notes or signaling a further check? Perhaps because she would have known that Fitzgerald could easily check the rest of her notes for this. And if there were no other signs of it then best to say "I don't know" why there is a question mark there.
No that question mark is ....... well a question mark, which may make sense if she thought or knew something was wrong with this piece of info.