It's possible it depends on the lead investigator, Jim. I know I've seen episodes where the two appraisers have looked for experts in a particular style or artist for other kinds of projects. Noteworthy is that this woman, I believe, is a historian, which suggests that a "primary source" like someone's memory would be acceptable as evidence.
And to answer the question, no, I don't recall them showing any other story, so the recollection could have been for later in the issue or other issues in the series entirely, of course, in theory. To be fair, it's an odd name for a former editor to pull out of a hat if he didn't work at Fawcett, so in that respect, I think it's plausible, even if not for that story.
