Mr. Hankey, the Christmas Poo - S1-E10
Character mistake: When the class are practising the nativity, Mrs Broflovski comes in and berates Mr Garrison for casting Kyle in the part of Joseph of Arimathea, but Joseph of Arimathea wasn't the husband of Mary, Jesus' mother, but a disciple of Jesus who helped in the burial of Jesus after his crucifixion.
Chosen answer: The Council believed that Jor-El was being an alarmist, that the changes in Krypton's core would only result in the planet's magnetic fields shifting rather than the beginnings of a chain reaction that would destroy the world.
Captain Defenestrator