I like picking up on mistakes while watching movies.
One of my all time favorites was 48 Hours.
After Nick Nolte gets Eddie Murphy out of jail, he handcuffs him in the car.
The next shot is ano overhead shot of them driving in the convertible, with Murphy's arms stretched out, the right on top of the passenger door, the left on the back of the seat.
Next scene they stop the car and Eddie is handcuffed again.