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: During "Control", Blaine's jacket can be seen repeatedly switching from closed to open. Most noticeably when the chorus shouts "oh yeah" and he's seen high-fiving another member of the group on the right of the screen. This is shown two consecutive times from two slightly different angles. The First Time his jacket is open, the second time it got buttoned up. (00:28:25)
Answer: According to IMDb.com, Ian Brennan, one of the "Glee" writers and producers, is listed as the uncredited narrator voice.
Michael Albert