The Field Where I Died - S4-E5
Continuity mistake: When Scully is searching through the pictures to find Sarah Kavanaugh and Sullivan Biddle, she turns the photographs over and they have a label on them to say who they are. Yet when the shot changes angle to show the photos from the back, the labels have disappeared.
Answer: He was being facetious. He doesn't specifically know that information, he was merely giving examples of the types of information he has access to.
I think so too.
lionhead