When Jean-Charles throws Ponytail off the roof, he does so by tossing him backwards by throwing his ankles up, causing his body to tip over the railing, upside-down. However, when the camera cuts to a wider shot, Ponytail is falling backward right-side up again, almost in a standing position.
The faucet in the doctor's lounge is covered in mold and scale at it's base. No sink or tap ware would be allowed to be in such a state in a hospital as it would be breeding ground for mucormycosis and other fungal infections.
When Pommier pulls the developed film out of the sink, it's clearly a 35 mm film strip from a movie with the according single frames. Pommier even looks at it in that orientation. As he was shooting with a standard SLR photo camera, the images should be oriented lengthwise on the strip.