Other mistake: It isn't clear if the poster of the Solar System outside the school was cut off on the right, showing half of Neptune, or if the ninth planet at the time (Pluto) was accidentally omitted. IF the poster was supposed to be complete, its exclusion of Pluto would be an error for the time period (1969) because Pluto was not downgraded to a "dwarf planet" until 2006. Perhaps, only half of Neptune was shown in order to not have to address the changed status of Pluto, making this a deliberate mistake. (00:32:36)
Suggested correction: Neptune isn't cut off, it shows as a complete circle on the "poster" (looks more like a board).