A Very Glee Christmas - S2-E10
Corrected entry: In "A Very Glee Christmas," Artie receives a ReWalk. Over the following seasons he is never seen using it. If this was the only way he could possibly walk, why doesn't he use it?
A Very Glee Christmas - S2-E10
Corrected entry: At the end Artie is given a ReWalk by Coach Beiste to help him walk again. However, at the time, the ReWalk was only available for use in rehabilitation centers, and not yet for personal use. In addition, it's highly unlikely that Coach Beiste would have the funds to buy a ReWalk.
Correction: The ReWalk became commercially available in January of 2010. Since it's entirely likely that a high school football coach might have contacts in the field of Sports Medicine, Coach Bieste probably just pulled a few strings and got one a few days early.
The Rocky Horror Glee Show - S2-E5
Corrected entry: When Finn and Rachel are singing "Dammit Janet" during "The Rocky Horror Glee Show", the shape of the heart that Finn drew on the whiteboard behind them changes several times.
Correction: This is a deliberate mistake and a tribute to the original Rocky Horror film, where the shape of the heart changes. Most people think this error was deliberate in the original film too.
Corrected entry: The posters that Lauren puts up of Quinn's former appearance say "Vote for Lucy Caboosey" on them, yet Quinn only told Lauren she used to be called 'Lucy Caboosey' about 5 minutes earlier.
The Sue Sylvester Shuffle - S2-E11
Corrected entry: During the scene where Rachel and Mercedes go and have coffee with Kurt and Blaine, on the cups half-hidden beneath the cardboard are the characters names, this is most noticeable with Rachel's and Blaine's cups.
Correction: Many coffee houses write the person's name on the cup so the barista knows what name to call out when the drink is finished being made. Not a mistake as it is the character's name on the cup, not the actor's.
Corrected entry: During "Night of Neglect", Will writes on the board that 5,000 times 0.25 is 20,000. That's incorrect, 5,000 times 0.25 is actually 1,250.
Correction: It's actually 5000 / 0.25 = 20,000 He's saying they would have to sell 20,000 pieces of Taffy at 25cents each to get $5000.
Correction: This was as a joke, as revealed in a cast interview. They knew that the math was incorrect but kept it.
Correction: It's mentioned later that it broke shortly thereafter.
Captain Defenestrator