The airplane depicted as flying Peggy in to JFK International Airport is a Boeing 707 when coming into land, but changes to a Boeing 727 when taxiing to the gate.
As Gene and his sister argue in the kitchen, the amount of milk in his glass keeps changing between shots.
At 13 minutes, Gene is in his Mom's room, and the lamp and pictures on the bureau behind him move around depending on the camera angle.
As Gene and his father walk to the front door of the house after the first day, the camera is backing up when it hits a flower that is sticking out from a hanging basket to the right.