Other mistake: When Mulder opens the body bag containing the "partial" remains of Max Pfennig (AKA Paul Gidney) a pulse can be seen beating in the right side of the corpse's neck. (00:18:10)
Other mistake: The landing plane is shown in a incorrect scale - it's too small compared to the sedans chasing Mulder and Scully. (00:32:30)
Other mistake: Sergeant Louis Frish had not enough time to walk down from the air traffic control tower to meet the agents since he was on the top of it when Mulder and Scully drive up to the tower - two persons can be seen on the top of the tower. (00:21:45)
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