Some shots of Superman "flying" from right to left are flipped, as evidenced by the backwards "S" symbol on his chest.
At the Beginning of Chapter Six, the outline of the hole Superman's about to make in the barn door is already visible.
At the climax of chapter twelve, the villains turn their heat ray on the Daily Planet building, causing all the mechanical devices to spark. As Clark Kent, Kirk Alyn shields his face, but the radio on his desk fails to give off any sparks.
In chapter one it is reported that Luthor has been placed in solitary confinement. However, when Luthor is shown in his cell there are two bunk beds.