When Richard holds the knife out to Eleanor in the dungeon, the knife reverses orientation and his grip on the handle changes between shots.
Henry breaks the ice on his water basin in order to wash, but the room is warm enough that no one's breath frosts the air.
Eleanor refers to syphilis in one of her speeches, an impossibility in 1183 England. Syphilis was not named such until 1530 by Hieronymus Fracastorius. Regardless of whether Europe even had the disease prior to 1200, it could not have been known by that name to the Queen.
When Henry has locked up this three sons in the cellar, he says that they are locked up together with the Port (wine). However, the term Port has only been in use since the 17th century.