Continuity mistake: Agent Doggett holds the rubbings in his hands and after a while, he hands them over to Agent Reyes. However, when filmed from behind Doggett, the rubbings are in the same position in both situations. (00:07:45)
Continuity mistake: When Agent Scully is leaving her apartment to meet Agent Doggett and Agent Reyes, her mother is holding William in her hands. Depending on the shot, William's head is turned right or left. (00:21:30)
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