When Bill/Mike opens the cottage door, he leaves the key in the lock and swings the door open to let his wife in first. As they pass through the door, the key is out of the door and in his hand.
When Bill is holding the revolver after the initial scuffle with George Conover, as the camera angle changes, his index finger moves from outside the trigger guard to the trigger and then outside the trigger guard again.
There is no way Bill's prison suit could fit inside the box he carried out of the "Idea Taylor" shop where he bought a new suit.
When Bill and Cay are fleeing to Easton, Pennsylvania in her brother's car, a shot of the car's dash shows the speedometer at about 55 mph, but all of the other gauges - temperature, fuel, oil, and amps - are as if the car is turned off.
When Steve Cochran's character leaves prison, he boards a bus while being spied on by a mystery man (reporter) sitting in his car. When the bus drives away, the reporter starts his car and begins to follow the bus. As his car drives away, two men and a spotlight are clearly visible in the left rear window.
When Bill goes to see Cay in New Jersey, a cab is shown going over the Triborough Bridge, which connects Manhattan to Queens - not New Jersey, which is in the opposite direction.
While they're riding in the car on the tractor trailer, Clark sticks a cigarette in his mouth. Even if they kept the windows closed, the smoke would undoubtedly draw attention.
When Clark orders a beer, Gatch asks what brand. Monroe then asks for one, too, but Gatch doesn't ask him which brand he wants.
Bill asks Cay if she is going somewhere with the wounded detective. She says, "I'm staying as far away from George Conover as I can". The next scene, Bill notices a newspaper story about the shooting, which reports detective Conover's first name as Harry.