In a scene with King Louis XIV and Mlle. de la Valliere, they are talking as they are seated together. In that scene, Mlle. de la Valliere's necklace is long, yet in a closeup the necklace almost looks as if it was a a different one, because it sits high up on her neck.
In one scene, the king is eating grapes while he's in bed talking to Fouquet who stands to the side. The king uses his left hand to eat . The camera changes and suddenly he's using his right hand for the grapes.
In one chase scene, a character fires a pistol three times in quick succession. 17th century firearms had to be reloaded after each shot.
Louis XIV offers "a million Francs" (and other amounts). The Franc was not adopted as currency in France until the 19th Century.