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.
Shanpû no hangeki! Hissatsu shiatsuken wa mimo kokomo ubau - S1-E16
Revealing mistake: In his close-up when he grins at Ranma after his request to help him figure out what happened to Akane, Ryoga is drawn really obviously with the hair going under his eyebrows. (00:15:00)
Revealing mistake: The ghosts often cast shadows.
Suggested correction: You can also hear their footsteps. But I'm not sure this is a mistake, just their own perception. Within the ghostly world they appear and act just like they would in life.
The ghosts are manifestations of energy, therefore they have no physical body to block light. Even if in the ghostly world, physics are physics and there should be no shadows.
Revealing mistake: Angelica and the other children are about to crash through the door to attack Lyra and Will. As Lyra runs past a cabinet, a lamp sitting on top is knocked over and crashes to the floor. Dafne Keene, who plays Lyra, reached over and very obviously pushed the lamp to the floor.
Dinner Party - S1-E4
Revealing mistake: Issac is reflected in the cabinet door when Sam is asking for the ghost's help.
Suggested correction: When was it established that the ghosts' reflections aren't seen?
The Cavern - S1-E10
Revealing mistake: When Jonathan and Nicky are running out of The Cavern during the rockfall a cabinet is knocked over by the vibration, but you can see that it is pushed over by someone with a stick.
The Darkest Hour: Part Two - S4-E2
Revealing mistake: At the very beginning of the episode, as the knights are about to send Merlin to Camelot with Lancelot, the knights walk towards the camera. As they do, there's a patch of green screen the special effects department must have forgotten to remove between Sir Elyan and Sir Percival. (00:02:10)
Revealing mistake: When everyone is supposed to be frozen, the neighbor girl standing behind the car can be seen moving her hand onto the car. This happens as Monica says "I'm not afraid of you, Wanda." (00:24:25)
Revealing mistake: Janet is holding a coke in her hand that she is supposed to be conjuring up but is already holding it.
Flash Gordon and the Planet of Death - S1-E1
Revealing mistake: In the flashback of the scientists' fate on the planet of Death, the sole survivor manages to run away and avoid the ray of "Belfagore" (which is just a big flashlight). Problem is, he does not; before hitting Bending behind him, the beam fully lit up his back, but he suffers no adverse consequences, no dropping dead for Jefvus. (00:06:40)
Revealing mistake: When the assistant gets thrown into the wall by the brain controlled Gar-tiger, there are already marks on the point of impact, from previous takes.
Revealing mistake: When Caleb arrives, as he's talking to Billaba and Grey, his Padawan braid clips through his cloak as it sways back and forth. (00:02:05)
Revealing mistake: When Roberta Halton knocks Rob unconscious, you can see that the blunt object barely even makes contact with his head.
Revealing mistake: During the opening theme, when the children are watching the magician, you can tell they were not actually filmed together. The magician scenes are filmed more professionally using a sharper tape or film image, whereas the children scenes look more like a standard fuzzier film-type such as on a projector (primarily used at that time).
Doug Takes the Case / Doug's Secret Song - S2-E1
Revealing mistake: The framing of this entire episode is such that the edge of the animation cels is visible. Noted on Paramount+.
Escape from the Happy Place - S4-E5
Revealing mistake: When the coach is killed by the monsters, the blood splatters onto the camera lens. The blood stays in one place until the camera slightly pans and it moves with the camera.
Revealing mistake: During the final battle there is a dual between Julius Caesar and Gannicus. At one point Gannicus spins Ceasar around and he is shown to wear modern day underwear.
Revealing mistake: The bullets the priest takes out of the ammunition tray have no primers. (01:01:33)