Revealing mistake: "Alan a Dale": Lady Mildred rides side-saddle. But when Gisburne gallops away with her, some shots reveal that the stunt woman riding the fast-moving horse is astride it full straddle. Her skirt is blown back just enough to see a brief glimpse of the stunt rider's real leg on the horse's right, and the fake pair of legs in side-saddle position on its left. For just a moment, the lady appears to have three legs.
Revealing mistake: "Robin & the Sorcerer, Part 2": To rescue Marion, Robin kills the bad guy by stabbing him with the silver arrow. A few moments later, after much writhing and screaming, Robin pulls the arrow from the corpse. But its tip and shaft are perfectly clean. Not a drop of blood in sight.