Other mistake: When Mulder and X are standing outside the Mulders' summer house, we hear that it is raining, but there is no sign of rain on neither of them. (00:17:50)
Visible crew/equipment: While Fox is fighting the agent in the underground garage you see a crew person on the right side of screen for a split second. (00:38:55)
Continuity mistake: In the pre-credits sequence when the gunman is shot by the police officer, he initially clutches a wound on his right side. When he is shown lying down, the bullet wound is higher up and on his left side.
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