Deliberate "mistake": It's completely impossible that the sound of the tape(that sounds like "Fox Maytrink") is in fact "Your time has come,Killer".

Continuity: General Callahan tells Mulder that the man he saw in his office said his name, but all he said was, "Your time has come, killer".

Continuity: General Callahan, who is referred to as General Callahan throughout the episode by Mulder, gets called "Lieutenant" Callahan in the last scenes in the steam-room, while lying on the floor.