Die Hand die Verletzt - S2-E14
Factual error: Mulder sees water going down the drain counterclockwise and says something is up since all water in the northern hemisphere drains clockwise. This is not true. Water can drain in both directions in both hemispheres. Things like convection currents, basin design, and residual swirl from filling the sink have a much greater influence. You would have to drain a small ocean to see the Coriolis effect, or use specially-designed test apparatus. See http://www.snopes.com/science/coriolis.htm and http://www.physics.ohio-state.edu/~dvandom/Edu/newcor.html (scroll down to *5.2. Water Going The Wrong Way Down The Sink* near the bottom of the page).
Die Hand die Verletzt - S2-E14
Continuity mistake: Having finished his conversation with Scully by the tree stump, Mulder walks away. However, in the next shot he again starts to walk away from Scully and from closer than before. (00:07:30)
Die Hand die Verletzt - S2-E14
Factual error: The loss of blood Shannon suffered was definitely insufficient to be the cause of her death. (00:25:00)
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