Continuity mistake: When Mulder gets out of the car, it's dark outside, but when the helicopter comes, it is still daylight. (00:25:00)
Continuity mistake: Pusher loads the revolver with one bullet, leaving five chambers empty. When Mulder picks it up and points it at Pusher, the bullet can be seen in the cylinder, just to the right of the gun barrel. Later, when Mulder begins to slowly pull the trigger for the third time (aiming at Scully), we see the cylinder turn to Mulder's left. Problem is, with the bullet situated as it was when Mulder picked it up, the bullet would have moved to the barrel and been fired the first time he pulled the trigger, killing Pusher. Instead, it fires on the third pull.
Continuity mistake: When Mulder is at Ground Control and the woman is telling the space ship that they're going into fly-by-wire mode, the Mulder's visitor pass changes from beneath his jacket to above his jacket between shots. (00:20:00)
Other mistake: When Doggett starts clawing at the freshly plastered wall, he does so at just below his eye-level and blood starts pouring from the hole he makes. The dead woman inside the wall was stabbed in the lower abdomen; there's no way that blood from the abdominal wound would've seeped through the wall at the level he was digging.
Continuity mistake: When Mulder pulls the nail from Blockhead's nose, the pliers are at The End of the nail, but in later shots it changes to the middle and then back to The End.
Plot hole: When Mulder and Scully are going to the town/city where the disappearances took place Scully says they should stop so she can walk the dog. Mulder says OK because he has to ask for directions yet the next scene we see is Mulder and Scully interviewing Dr. Faraday. How did they find him if they didn't know where they were?. And after that we see them at a store where they do ask for directions. (00:08:30)
Continuity mistake: When Max bleeds out his ear, the blood stain on the pillow changes when Mulder and Scully see it. (00:32:10)
Unrequited - S4-E16
Deliberate mistake: When Mulder is about to go into the metal detector he puts his gun on the counter. He goes through the metal detector on his cell phone but his keys set it off, when he steps through again it doesn't go off. No cell phones can go through metal detectors without setting it off.
Soft Light - S2-E23
Plot hole: If the shadow acts like a black hole and tears apart all atoms that enter it why does it only seem to affect people (but also their clothing and anything else on them)? Surely Dr Banton would be destroying everything around him.
Factual error: At The Beginning of the scene, XO Johanson is looking through the periscope. However, it is nonsense, because the submarine was in silent running, and the Japanese destroyer was circling it, so the sub must have cruised in deep submersion. The water depth there was approx. 270 meters, as the French salvage team claims at The Beginning of the episode. There is rarely any significant light beyond 200 meters. Looking through the periscope in these conditions would be completely useless. (00:32:25)
Revealing mistake: At the very beginning of the scene when the bomb is shown, in the lower part of the screen a moving red spot appears which probably comes from the reflection of the bomb's red diode in the camera. (00:36:50)
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)
Factual error: It's quite strange that only after Mulder looks into the ashtray he realizes that the Smoking Man has been in the car. Mulder should smell the scent of cigarettes immediately after entering the car, especially if he is a non-smoker. (00:36:05)
Factual error: The crew are supposed to be French. However at The Beginning of the episode we can hear them talking in French with a Canadian accent.
Deliberate mistake: When the unconscious, naked Asian doctor is removed from the warming tub, his hands are clasped over his crotch to protect his modesty, despite the fact that he shouldn't be able to do that, since he isn't conscious and his previously frozen limbs are now pliable and relaxed due to the heat.
Factual error: This episode begins with Scully doing a voice-over about the incredible nature of our universe. The scene is very impressive visually, and would have been from the aspect of her oral presentation had it not been for a major error in the script. She says (more than once) that the universe is made up of matter and gas. This should have been "matter and energy". Gas is a form of matter.
Plot hole: On the phone, Scully asks for the report on her sister to be sent to the San Diego F.B.I field office (since she is visiting her brother and his wife and so is not in Washington), but the package is sent to her brother's home. Even if 'Danny,' whom she asks for the file, decided to be helpful and send it directly to her, her brother's address is not likely to be the one in her personal file, plus she didn't mention that that's where she'd be staying.
Other mistake: Eve 6 says that ordinary human beings have 46 chromosomes, while the Adams and the Eves have 56 chromosomes. This makes 10 additional chromosomes. However, Eve 6 also mentions that they have additional chromosomes number 4, 5, 12, 16, and 22 - only 5 additional chromosomes. (00:22:40)
Suggested correction: There is no mistake. Normal humans have 23 pairs of chromosomes: two 1s, two 2s, two 22s, and either XX for females or XY for males. 46 chromosomes in total. The Eves have 5 extra pairs of chromosomes, or 10 extra individual chromosomes. So what Eve 6 said tallies up. In reality, this many extra chromosomes would surely be lethal.
Factual error: When Scully is performing the autopsy on Leonard Betts' severed head, she states "As remains are incomplete, all observations refer to a decapitated head." This phrasing is redundant. The proper terminology would be "disembodied head." As a medical doctor, Scully should know this.
