During the metro chase, close-ups of Jules shows the collar of a white tee-shirt underneath his buttoned-up shirt. However, in both previous and following scenes, he is without the tee-shirt.
At about 27 min. into the movie, when Jules and Alba are listening to the tape on their headsets, behind them there is a shelf with some booze. The Martini bottle is facing the camera with its front label. The camera does a pan around the column and, when it comes back to Jules and Alba, the back label of the Martini bottle is now facing the camera.
When Nadia is just exiting the metro station and runs into Jules, he is wearing his postman's cap. Later, in the police station when Paula is recounting Nadia's death, the same scene is replayed, except this time Jules is not wearing his cap. However as this is a recollection the details aren't always the same.