Revealing mistake: The firefighters, apparently the fastest men in the universe, appear no more than 10 seconds after the fire starts.
Revealing mistake: When Eric picks up Cory to show him the "For He's A Jolly Good Fellow" dance, Cory screams that Eric is going to knock over the candles, upon which one of the candles on the desk is knocked over and sets fire to the curtains. If you look closely, neither Eric or Cory bump any of the candles nor the desk they are on, the candle just tips over on its own, suggesting an off-screen crew member used wire or string to pull the candle down. (00:07:18)