Other mistake: At the beginning of the film a bomber is crashing. As this is happening another bomber is stationary in the sky.
Other mistake: When the parent monster is just about to enter Piccadilly square, for a brief moment a view of a bus is shown. The writing on the bus is reversed.
Other mistake: When Regret, Jake, Pilar and her father are escaping from the Comanchero village, there's a close up of Jake (Wayne) in the back of the wagon shooting a rifle. The scene shows him shooting left-handed. It's a reverse print. Look at his "right" hand in the scene. He has a ring on his "right" hand ring finger. A few moments later, setting the wagon canvas afire trailing out the back of the wagon and shooting right handed, the ring is on his left hand as it is in the rest of the movie.