While watching the film, Five stops the projector to freeze frame on their dad. This is not possible. The heat from the lamp would melt the film.
Luther's revolver appears to be "double action only", that is, its hammer has no protrusion that can be used to cock it; yet a click is heard as Luther cocks it when he meets Vanya, and another click to uncock it when he decides not to shoot.
When Luther is sitting in the car (in 1963) watching Vanya at the farm you see his gun sitting on the seat next to him. You also see a seat belt draped across the seat. This is highly unlikely as seat belts in American cars were not standard equipment until as early as 1964.