When the mother of the little girl puts her to bed, she touches the light switch to turn out the light. It is the old push button type. She just lightly touches the bottom push button, but the buttons don't move, and the light goes out.
Close-up of Paddy Wagon shows hinges use Robertson screws which were only manufactured starting in 1908.
The police dig up a coffin of someone who has been buried alive and is rapidly running out of air. When they get the lid off the coffin in the nick of time, it is obvious that the earth on the left side of the coffin has been excavated. The police would have no reason to dig the sides out as all they wanted to do is get off the lid. In addition, the excavated space is too narrow for a shovel to fit.