At the beginning of the episode, the police state that the murder was committed with a "small-caliber automatic pistol". Yet later, when the execution of the murder-plot is shown in retrospective, a revolver is used.
The dress shirt buttoning of Captain Hastings keeps alternating between right-over-left and left-over-right throughout the episode.
On the marriage license, the year at the top is given as 1930, however in the following text it is given as "tausend neunhundert zweiunddreissig", meaning 1932.