Anasazi (1) - S2-E25
Character mistake: Mulder asks Scully about "the fourth commandment about obeying the Sabbath, the part when God made heaven and Earth " However, Scully as a Catholic should know that this is the third commandment for Catholics. This is also an indirect indication that Mulder was raised in Jewish religion. (00:09:25)
Character mistake: Surprisingly, it took Scully quite a long time to realize that the tattoo on the victim's forearm is in Cyrillic lettering. (00:24:00)
Answer: As he stated many times throughout the series, Mulder needed Scully to be sober and skeptical. Whenever Scully's skepticism wavered and she started questioning her own rationality, Mulder would try to restore her sense of skepticism, because he needed her to be clear-thinking.
Charles Austin Miller