When Anthony is reciting poetry over the balcony through the speaking funnel, the funnel has a wide mouthpiece on one end. When Anthony returns through the window into the dining room, the mouthpiece is gone.
When Sebastian and Charles set off with strawberries and a bottle of Chateau Peyraguey, Sebastian starts the car with a half-turn on the starting crank. In actuality, it takes much more effort than that. A four-stroke engine requires at least an intake stroke and a compression stroke before firing, and that's one full turn.
In voiceover, Charles describes his letter from Sebastian as being written on paper with a black border. The shot of the letter shows a thin black border, which is better visible on the envelope.
After the haircut scene, Hooper's hair clearly hasn't been cut anything like short enough to have satisfied the C.O.