I think that there were about 800 people attached to that unit. That someone doesn't remember one person who came a few times and read flight manuals is not at all surprising. They may have never even been on the base at the same time. What a thin accusation.
Actually there WERE people that remembered him, several of them if I remember correctly. I know that Lt. Col John Calhoun was one. He pointed out the fact that Bush signed in on the Duty Sheet that Calhoun kept on his desk.