When Alexander Carston ordered one of his main henchmen to take Bradford to the castle, he called him Richard. However, on every other occasion before and after, the henchman was referred to by Carston and everyone else as Rich.
At the castle when one of the law enforcement agents kills the gangster Rich with a machine gun; the entrance door is riddled with heavy gunfire and the bullets penetrate the door. However directly on the other side of the door are other agents and therefore they should have also been struck by gunfire but when they busted through the door immediately thereafter no agent was hit by bullets or shrapnel from the door.
In the castle when one of the gangsters was fleeing through a window, the sound of the machine gun firing went on for much longer than the visual of the damage done to the window, walls and the gangster.
When Richie takes Bill away to the castle, the feet of crew members and camera equipment are clearly reflected on the car.
The lawmen approach the gangsters' hideout but are stopped by a tall chain-link fence, which they fear may be electrified. They go round to the back of the house, and start climbing through the windows. There is no explanation of how they go through or over the fence, or if indeed the fence stopped halfway round the house.
When Julie is kidnapped by two gangsters, in order to show how cool and poised she is, she says, "I've never seen you two before," then adds, "Which one of the Rover Boys are you?" Of course, it should be "which of the Rover Boys," as there are two of them.