Big Pink Loser / Bubble Buddy - S2-E3
Revealing mistake: Big Pink Loser: When Patrick is answering phone calls, the third time he picks up and says, "No, this is Patrick", the anchor symbol on his hat briefly vanishes. (00:04:36)
Suggested correction: This mistake can only be detected by freezing the film and advancing frame by frame. It is not visible while watching the film at a normal running speed. According to the rules of this site, this invalidates the error.
So, I reworded the mistake to say that it "briefly vanishes," because it's actually gone for a few frames, not one. I did not advance frame by frame to find the error. If you watch the scene at normal speed, it disappears for a brief moment, then comes back. I assume this correction might have been made without watching the scene, especially since the show was referred to as a "film."
This is not true. You can see it disappear if you watch it at normal speed; it does not require pausing at all. At least, I am able to see it.
Big Pink Loser / Bubble Buddy - S2-E3
Revealing mistake: Big Pink Loser: When Patrick says, "Why can't I do anything right?", and starts hitting his broom on the floor, the drinks that are supposed to be on the customers' tables are instead layered behind them. (00:05:18)
Mermaid Man and Barnacle Boy III / Squirrel Jokes - S2-E4
Revealing mistake: When we see Billy get told about the stupid squirrel, he has a sleeve going through his arm. The moment he starts talking, the sleeve disappears and his arm extends over his shirt. Around the end of the shot when he's being pulled away, the sleeve returns.
Dying For Pie / Imitation Krabs - S2-E6
Revealing mistake: In the episode "Dying For Pie", you can see Mr. Krabs' legs disappear when Squidward says, "But you can't pay me enough to act brotherly on that guy!"
Revealing mistake: At the end of "Wormy", Patrick's eyes are missing.
The Secret Box / Band Geeks - S2-E14
Revealing mistake: When Squidward asks who has played instruments before and Plankton responds, look at Plankton's triangle. The bottom disappears for a split-second.