Johnny is seen using a suppressor on his revolver; this is a common mistake in films, as the gap between the cylinder and barrel renders a suppressor mostly ineffective.
When the Wilsons are driving down the highway, the position of the gear shift is in Park. If it was a standard transmission, it would be in second gear. Both should be in the down position.
Midge Ware is billed as "Doris Johnson", but in her first meeting with Frank Dorella, her character insists her name is "Doris Jackson".