Revealing mistake: When Sinbad and his men are fighting the pagans' "god of the single eye" centaur, Margiana the slave girl is shown screaming briefly. If you look closely, you can tell it isn't Caroline Munro, but a close look-alike.
Revealing mistake: When Tee Hee bends the barrel of Bond's Walther PPK, in the close-up, the score marks where the barrel has been pre-cut are visible.
Revealing mistake: When Maturette dies at the end he cannot close his left eye all the way because of the totally noticeable fake contact lens he is wearing.
Revealing mistake: After the jailbreak, a number of reaction shots for which the shot background is the villagers in the speeding wagon, not only do they not "bounce" with the wagon, they are not even animated.
Revealing mistake: Richard Roundtree is quite literally butt naked during his stick fight in the Emir's stable towards the beginning of the movie, except in one shot where the person in frame is wearing blue sweatpants. (00:12:50)