Other mistake: As the surviving characters discuss the fate of Westeros, 2 plastic water bottles can be seen tucked behind the chairs they're sitting on.
Factual error: When Roy is electrocuted and falls from the roof, after Karen uses the defibrillator paddles on Roy, she lifts both paddles, looks at the EKG monitor and says "He's converted." How exactly could Karen have known that he's converted? It's impossible for the EKG monitor to show anything at all. Either the defib paddles have to be in contact with Roy's body for the "quick-look" to get a reading, which they weren't, or the ECG electrode discs have to be on Roy's chest connecting him to the EKG monitor, and they weren't. As an aside, just watching Marco having problems attaching the air mask, and quickly glancing up towards the camera frustrated, then giving up is priceless.
Girl Trouble / School Dance - S3-E18
Continuity mistake: Besides the fact that when Helga is sharpening her pencil, the desk arrangement changes, one of the students visible when she looks at Arnold is... Helga. This happens because the shot is taken from the episode "Helga's Love Potion."
Continuity mistake: When the class is in Arnold's esophagus, Tim says something, then it cuts back to Ms. Frizzle. Arnold is sitting in the back seat of the bus.
Angelville - S3-E1
Continuity mistake: After Jody kicks and knocks Bruneau Boyd to the ground, Jesse peels out in the pickup truck and Bruneau's body disappears, even though it should be lying next to the truck as it quickly departs.
Other mistake: During the Pokérap, when the Poliwrath name is said, the Pokémon shown is actually Poliwag. Also, when the Graveler name is said, the Pokémon shown is actually Geodude.
Revealing mistake: When Sgt. Troy throws the grenade at the Gestapo agents barricaded behind the table, it is thrown wide right, yet the pyrotechnic explosion is dead center of the table barricade.
Family Ties - S1-E22
Visible crew/equipment: After Rygel's transport pod returns to Moya, as the docking bay door slides open, in the shot facing everyone while they have their weapons drawn we can see the bare floor. However, when Aeryn checks Crais for hidden weapons and then as D'Argo approaches him, there's a blue crash mat on the floor. Then it vanishes again.
The Magician - S3-E4
Revealing mistake: When Oliver meets Thea at the Grind and Jot Cafe (Which looks unsurprisingly like CC Jitters) you can see the cups on the table are from CC Jitters. (00:20:50)
Encounter at Farpoint (1) - S1-E1
Revealing mistake: When Q freezes Torres on the bridge, it is easy to tell that directional hoses were used for the effect. (00:06:25)
Kobol's Last Gleaming (2) - S1-E15
Visible crew/equipment: In the scene where Starbuck attempts to retrieve Apollo's arrow, a crewman in a red tee shirt and dark vest can be seen standing just behind and to the right of the display case as she is shooting out the glass.
Plot hole: Hippolyta tells Hawkgirl of Aresia's background of being born in the outside world, the war in her country and right up to her drifting to the shores of Themyscira. It would be impossible for her to know anything of Aresia's background as in part two, it's explained that the captain of the ship who saved Aresia died shortly after reaching Themyscira and therefore would not have been able to tell Hippolyta anything.
Deliberate mistake: When the Doctor begins to "fade" in the transporter room his mobile emitter fades with him. Since it's made of solid matter and is not a hologram, this shouldn't be possible.
Snow Falls - S1-E3
Visible crew/equipment: When the horse carriage is ambushed, just as Princess Abigail can be heard screaming "Please, help me", the camera pans downward and a horse wrangler wearing a blue baseball cap can be seen in the lower left hand corner, hiding behind one of the horses. (00:03:20)
Is There in Truth No Beauty? - S3-E5
Other mistake: In the final scene, Kirk is still in the transporter room, but does not have on a visor when the ambassador transports out. Even if he did, humans can still go mad if wearing one and that's why Spock operates the transporter. Spock has his visor on, but then you see Kirk walk out of the transporter room without a visor and he is not going mad.
Continuity mistake: In the introduction, when TJ pulls the ball off Gus, Gus is covered in gum. When they are walking into the school, the gum has disappeared.
Factual error: Wanda's father opens his briefcase of DVDs and one of them is Malcolm in the Middle. But the bomb that killed him fell in 1999, and Malcolm in the Middle didn't start airing until 2000.
Factual error: A character in the episode has invented denim, but denim was invented in 1873 and was being used widely up to the time period of the series, which is set in 1893.
Suggested correction: The entire series was set in an alternate history of sorts, so most, if not all, historical "inaccuracies" cannot be regarded as mistakes.
Continuity mistake: When Jack speaks to Michael and Jin, as they build the raft, and then when he walks up the beach and inquires about Sawyer's trouble with his head, the backpack that Jack carries on his back is nylon, black/green with white trim. Yet, when Sawyer asks, "Sensitivity to light, that bad?" the backpack is suddenly transformed into solid black leather, of an entirely different style. Then, in following shots it jumps back and forth. (00:16:40)
Suggested correction: Actually no, in that angle and the way Jody kicked him away hard from the truck it's possible he landed a lot further away than you might think.
lionhead
Before I submitted the mistake, I did take into account the angle and the distance that Jody kicked Bruneau, replayed the scene several times, and he did disappear, as there was a sidewalk and a length of lawn leading up to the apartment building where Bruneau should have been lying as Jesse and Jody took off in the truck.
Scott215