When Hitler wears his uniform with the brown coat and white shirt he wears a black tie. The real Hitler, when wearing this uniform, would wear a brown tie with a tie pin of an eagle astride a swastika.
In a scene when Hitler and Freud are talking, Hitler is wearing his gray army uniform with a swastika armband. The armband should not be there. An emblem of a eagle astride a swastika should be there.
The actor playing Hitler has blue eyes, as you can see when he uses a magnifying glass at the start of the film. The real Hitler had brown eyes.