Factual error: After he gets fired from his teaching job, Mr. Ryerson makes a living reselling the medical marijuana he receives for depression. At the time the episode was made, Ohio was not one of the 16 states (and District of Columbia) that had medical marijuana laws, and NONE of the states allowed it for treatment of depression.
Glee (2009)
1 factual error in show generally - chronological order
Continuity mistake: In "Wheels," when Artie is singing 'Dancing By Myself' and doing tricks in his wheelchair, the wheels on the back of the chair that prevent him from falling backwards disappear and reappear, depending on whether or not he is performing a trick.
Laryngitis - S1-E18
Sue Slyvester: See, that's the problem with your generation, you're obsessed with labels. So what if you like show tunes, it doesn't mean you're gay. It just means you're awful.
More trivia for Glee
Question: Who is the narrator for the previous episode montages?
Answer: According to IMDb.com, Ian Brennan, one of the "Glee" writers and producers, is listed as the uncredited narrator voice.
Michael Albert