Character mistake: When Sheldon arrives at the apartment with his Nintendo 64 in the box, he tells Leonard that they can play Super Mario 64. He then proceeds to say, upon finding a memory card, that they can pick up where he left off. Super Mario 64 does not make use of the memory card for progression, all of that data was saved on the cartridge.
Factual error: Sheldon states that the "Reinheitsgebot" would have severely limited the availability of mead in 1487. This is wrong for two reasons, the first being that the most commonly known version of this law wasn't introduced until 1516 and secondly this law only defined the price and the ingredients of beer and had therefore nothing to do with other alcoholic beverages like mead.