Continuity mistake: Puck butters the floor, and as Kurt slips and falls, The Substitute is not where she had been standing. The next shot, she's still there. (00:07:45)
Continuity mistake: When Will reads the newspaper review of their concert, the date on the newspaper is February 12, 2009. This date is impossible. Most of the Glee kids who graduated in 2012 were sophomores in season 1, and the only way to be in school around the February 2009 date is if the class of 2012 were 9th graders. Only this is not the case. Also, all the football or basketball episodes in season 1 would all be incorrect. The most likely date for Acafellas is September 2009.
Continuity mistake: The DVD Tina brings Mr. Chang. When she leaves she picks it up from the desk, in the last shot it is back on the desk. (00:17:38)
Continuity mistake: Puckerman is on a skateboard and then jumps on to the bench, but the skateboard just disappears.
Continuity mistake: While Jake is singing to Marley in history class, the clock drastically changes times from one shot to the next.
Continuity mistake: When Sam is talking to and kissing Nurse Penny in her office, Nurse Penny's lanyard keeps moving from the left side (on screen) of her name badge to the right side and also sits on top of the badge. (00:43:00 - 00:45:00)
Continuity mistake: During the song express yourself, whilst the girls are dancing on the stage Quinn appears to have a flat stomach but she is supposed to be pregnant at this stage.
Answer: According to IMDb.com, Ian Brennan, one of the "Glee" writers and producers, is listed as the uncredited narrator voice.
Michael Albert