The High Life / Best Friends - S2-E10
Deliberate mistake: In "The High Life", there is a scene where Stinky submerges his head in a tank of water. He delivers the line, "Gee willickers, it's still ticking", and everyone somehow understands what he is saying with his head underwater.
Suggested correction: Nobody responds to what Stinky says, so there's no reason to assume that everyone understood him.
Coach Wittenberg / Four-Eyed Jack - S2-E16
Continuity mistake: Coach Wittenburg's anchor tattoo changes color from red to purple in between shots.
Suggested correction: No, his tattoo is always red.
Magic Show / 24 Hours to Live - S1-E18
Audio problem: Helga rides past Arnold in a bus and yells "24 hours until you die!" or something like that. Her mouth never moves- it just stays open in an evil smile.
Suggested correction: Although it's hard to make out, her mouth is moving when she says that. Also, she says "23 hours until you die!" not 24.
Arnold's Thanksgiving - S3-E14
Continuity mistake: When Joey is shown in close-up, his missing tooth looks like it's there but it's covered with something black and his missing tooth keeps reappearing and disappearing in the last scenes.
Suggested correction: Joey never appears in this episode.
Arnold Saves Sid / Hookey - S2-E7
Revealing mistake: Arnold and Gerald's lockers don't have padlocks, like most of the others do.
Suggested correction: Like you state, most of the other lockers have padlocks, which means that some don't. You can even see some lockers without padlocks in the beginning. This is not a reason as to why Arnold and Gerald's lockers having no padlocks is a mistake. It more has to do with the fact that their lockers in particular should have padlocks, because they usually have them in other appearances. Edit: While I do agree with what I said, I now think that changing the mistake's wording would have been a better option than adding a correction, as Arnold and Gerald's lockers not having padlocks is still a mistake on its own.
The Aptitude Test / Oskar Gets a Job - S3-E9
Revealing mistake: The test paper Eugene put back in Harold's folder is blank.
Suggested correction: The paper is not blank. Helga used a purple pen to fill in her paper, and Eugene put it in Harold's folder. The paper is filled with purple ink.
