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)
Factual error: They sing Katy Perry's "Roar" before the song was even released. This episode is set in Spring 2013 and the song was released in August.
Answer: According to IMDb.com, Ian Brennan, one of the "Glee" writers and producers, is listed as the uncredited narrator voice.
Michael Albert