When Lee Hackett leaves town, chasing after his jailbreak son, Ed, he is riding a "right-maned" horse. When he catches up with Ed, he is on a "left-maned" (different) horse.
When the Sheriff and Purcell Avery go to the doctor's to question Mr Sieverts, the office door is locked. The doctor unlocks the door to let them in and then locks it again once they're inside. As they leave, the doctor pulls the door open - without unlocking it first. For that to happen, the door would have to be a prop that was never locked in the first place.