Toward the end when Ken's former cell-mate is at the house blackmailing Ruth, Ken pulls up and parks out front. In the subsequent scene when the police arrive, Ken's car is no longer parked in front of the house.
The name of the city Ken and Ruth flee to is spelled inconsistently. Sometimes as two words, sometimes as one word.
(at around 1 min) Two police officers spot the stolen car. When they turn around, the interior of the police car is reversed. Their badges switch to the right side, and the steering wheel and driver are now on the right - in other words the film is reversed. In the other views of the police car's interior the view is correct, with the steering wheel and badges on the left.
When Ken is pacing before Penny's birth, Kit suggests he stop to conserve shoe leather needed for the war effort. However, this scene is five years before the present-day time period of the remainder of the film, so it would have been happening in 1937 -- at least four years before the U.S. began its WWII war effort.
Ken tries to take a picture, at night, through a closed window. The flash reflected in the glass would have obliterated any image he was trying to get.