When Yvonne Müller (Marielouise Nagel) gets down to pick up her purse, Commissioner Krass (Gert Fröbe) gets up from his bar stool behind her twice.
When Commissioner Krass (Gert Fröbe) chases the perpetrator in a police car, during the part in the city the shop signs in the background are reversed - an indication for a reversed back projection.
When Wurster's Assistant brakes for the crossing Gekeler, Wurster reacts much too late. Together with the not-so-elegant back projection this is an obvious hint at the fact that the car is stationary and Peter van Eyck reacts badly to a cue.
The unknown perpetrator shoots out of the rear window of his colleagues' car at Commissioner Krass' car with a machine gun in full automatic mode. The subsequent bullet impacts however match much slower manual handgun fire.
In the cellar, Mabuse tells his henchmen to close the vault door, yet he himself has the remote control in his hand that he used before to open the door.