Take Me out of the Ball Game - S3-E24
Other mistake: When Peggy strikes Bill in the head in the softball game, he gets hit on the left side of his head. Later in the scene he is using an ice bag on his head but he's icing the other side.
Other mistake: When Don and Dr Smith are stealing Sesmar's control unit, look closely at the base of the electronic arch - Raddion is hidden from sight but the careful eye will see his golden feet.
Other mistake: In the Y valley travel agents sketch Smoke Too Much states that he can't say the letter C. But he uses several Cs before Bounder suggests he uses the letter K, even saying "I can't say the letter B." He says that he'd never thought of the letter K before.
Other mistake: In the scene where Drakken accidentally "clones" Bonnie Rockwaller instead of Kim Possible, he holds up a picture of Kim to compare the results of his experiment with the real thing. The Bonnie clone, completely encapsulated behind the glass of Drakken's cloning machine (as evidenced by the reflection of light off of it) somehow manages to get a hold of the picture despite this barrier. (She does this without having to break the glass.).
Other mistake: It is daylight outside when Cliff and Clair are talking, but when he turns the lights off to try on his light-up Father's Day gifts, it gets pitch black in the room.
Other mistake: At the very beginning of the episode, Fletcher wakes up in bed and his hair is perfectly combed.
Other mistake: In this episode, Shawn supposedly impresses Jules at their first meeting by "divining" facts about her family and cats. We never hear about the cats again and later learn that her parents have not been together for 30 years.
Other mistake: Right after Sam tells Carla he will sleep with the next woman who walks through the door, in the background there is an "Extra" (blonde-haired woman seen in the background behind Carla) who starts to cross right then turns and crosses left then turns right and stops and looks confused as to where she is to cross. Obviously she was given directions of which way to cross and when, but forgot. (00:04:15)
Other mistake: When the kids are opening their lockers, they enter the code, then pull on the lock to open the locker. The closed lock is still attached to the front of the locker. When they close it, it's magically locked again without them ever opening or closing the lock. In reality, these locks would be useless, or the locker doors wouldn't open.
It's About Time! (Part 1 & 2) - S1-E21
Other mistake: Near the end of the episode after they get back, when the camera zooms in on Phineas and Isabella, Isabella's face is gone - only her eyes remain, but after the camera zooms out her face is back.
Other mistake: Tails automatically knows Cosmo's name even before she introduces herself later on (English Dub version only).
Other mistake: When the opening credits are shown, the door to the basement is in the kitchen. In the beginning of the series the door is still in the kitchen, but in later seasons the basement door is in the laundry room, but in the opening credits it is still in the kitchen.
Suggested correction: I had noticed the same thing and thought it was a continuity mistake. However, in Season 3, Dan mentioned building the back service porch where Roseanne does the laundry. There are two basement accesses, the one in the kitchen, and what was probably the outside entrance in the backyard that is now enclosed inside the service porch. The family prefers using that one. Most houses, mine own included, have multiple basement access, one inside the house and one outside. In my state, it's a building code requirement for safety reasons.
Other mistake: The bridge jump scene in this episode is recycled from the season two episode "Labor Pains" where the van changes.
Other mistake: The bishop that Dougal talks to about religion being pointless is supposed to be Irish but when he is telling Ted about his change of heart, the actor's English accent slips back in for a few seconds.
Don't Fool With a Phantom - S2-E8
Other mistake: When the wax phantom appears behind Scooby and Shaggy the man who supposedly is impersonating him in the suit is in clear sight directly behind Fred Daphne and Velma.
The Strange Fate of Conrad Meyer Zulick - S3-E9
Other mistake: When Doc Donovan reads the wanted posters, the physical description of Heyes mentions dark brown hair and brown eyes, which fits Pete Duel. However, by this episode, Roger Davis had taken over the role. He has light brown hair and blue eyes.
Other mistake: It appears as if Steve is holding 3 $20 bills when he supposedly received $50.
Other mistake: Captain Eureka losing his finger makes absolutely no sense. He doesn't cry out in pain, there's no blood, and where the finger ended up is completely illogical. The finger didn't just sever on its own; it's shown that severing only occurs when passing through objects. Captain Eureka goes through a wall that is a good fifteen feet away from where the finger is discovered, and it is implausible to think it could have rolled there on its own.
Other mistake: During the hold up when Medhurst is sprung from the police van, the breakdown truck used to pull the doors of the van reverses towards the police van twice after releasing the chains off the doors before driving away, and the camera lights are reflected in the side of the white getaway car.