Plot hole: During the episode "Superstition", Onizuka thinks he has cancer because the magnetic pain-pads he was wearing created strange blobs in the X-Ray he has taken. However, given the fact that the X-Ray was so strange, doctors would have given him a complete physical, and noticed the pads much sooner. Here, they literally just assume he has tumors, and fail to ever take notice of the pads. Simply impossible, given the gravity of the situation. (Obviously, this is to pay off at the very end of the episode.)
Super Nova - S1-E2
Revealing mistake: When Stan, Xev and Kai are walking to the Memory Chamber, they seem to walk out of a two dimensional line at the lower left into the scene. The set and green screen weren't quite synched.
Audio problem: After Kate shoots an arrow at the mafia guys, she says "told ya." Then we hear Clint/Hawkeye say "yeah", except he's on camera and his mouth doesn't move, he doesn't even change his facial expression.
Factual error: Sir John Franklin, Francis Crozier and James Fitzjames all wear a crown over an anchor on their epaulettes, the rank badge for a captain with over three years in rank. This is correct for Franklin and Crozier, but Fitzjames only held the rank of commander, and should therefore only be wearing an anchor on his epaulettes.
Revealing mistake: When Grapefruit cannonballs into the pull, it splashes on Pear. But no sign of any wetness is seen at all on him or the diving board.
Factual error: In the last minutes, the show looks forward to future challenges, in effect a preview of the never-made 3rd series. The oracle says they must find "the golden fleece, woven long ago by the Stygian witches." But the golden fleece, or indeed any fleece, is not a woven fabric. (Today's fleece is a modern invention).
Die Glocke - S4-E6
Other mistake: When Jones is trying to convince Herr Waesch that she's the owner of the estate where his gala is being held, subtitles of his reply read "I personally procured this home. It's owners were French." The contraction "it's" should be the possessive "its."
Chapter 7: In the Name of Honor - S1-E7
Revealing mistake: When the big battle starts, Boba and Mando appear using their jet packs. As Boba lands with one foot forwards, sand is thrown up into the air, but the sand is a special effect coming from about a metre in front of Boba, not from the foot itself. The result is very unconvincing.
Episode #1.2 - S1-E2
Other mistake: The very first word of the opening title contains an embarrassing typo, considering it's the name of the main character: It reads "Maud'Dib", instead of "Muad'Dib".
Continuity mistake: Throughout the episode Lieutenant Abbie Mills' lapel mic changes from scene to scene. It goes from the Motorola Commander Speaker Mic to a standard Motorola mic without the orange emergency button, volume control, 16 channel selector knob and 2 programmable buttons.
The Greatest American Hero (1) - S1-E1
Continuity mistake: While Bill and Ralph are in the car, John Mackie appears under the ship carrying the case with the suit. After John places the case in the car's trunk he walks back towards the ship empty handed, but in the last shot of John standing under the ship he's still holding the case.
Other mistake: There is a countdown on the movie screen. It is then reflected in Dusty's glasses. But the numbers are not reversed in the glasses. (00:41:00)
Claudia and the Secret Passage - S1-E8
Continuity mistake: Dawn enters the library wearing open back clogs and exits minutes later in white sneakers and socks.
Factual error: Season 1, Episode 10: Lee is trying to get out of the underworld on his capsule with the rescued others. They all get in, and he closes the top hatch by turning the hatch wheel clockwise. Trying to take off, a wire becomes disconnected outside, and Lee has to go out again. He turns the hatch wheel clockwise, and this time it opens instead of closing. If it was clockwise for close, it should be counterclockwise to open.
Continuity mistake: The professor knocks a hole in the side of a tunnel and hot water and steam gush out. The group is then distracted by a boulder traveling through the tunnel. After the boulder passes, there is no longer any steam or water gushing from the hole in the wall.
Piratsy Under the Seas - S1-E1
Continuity mistake: When Jolly Roger hands the map to Dale, the map has either a dark brown border or not depending on the angle. (00:08:30)
Revealing mistake: When Edward opens the gate to let Tracy in, we then see a shot of Tracy and you can see it is repeated footage of her from when she met Edward for the first time.
Factual error: When Jane is putting up the lost poster, the number to call is 1-800-saw-him. However, this is only a 6-digit phone number when it needs to be 7-digits (not including the 1-800 part).