Jack and Ally are walking toward each other in a gas station parking lot during the trip to Arizona. Ally is wearing a blouse when the shot starts, but when they meet and embrace, she's wearing a leather jacket.
When Bobby takes Jack home from the rehab, they arrive to the house, Jack tells him he idolized him, then shuts the door and walks away - Bobby immediately backs up the car and leaves. Moments later, when Jack enters the house, he is carrying a suitcase and his guitar, none of which has he taken out of the truck.
The goof item below may give away important plot points.
Just before Jack hangs himself, he feeds the dog inside the house. then goes into the garage, shutting the dog inside the closed house. Later, when the audience is shown Jack's
legs hanging, through the garage windows, the dog is outside in the driveway.