Watch Salut, voleurs! (1973) Official Trailer

In this French crime caper film, a young misfit who has grown tired of his job as a bank teller deliberately gets fired. When some underworld characters ask him to share the layout of the bank so that they can more effectively rob it, he does. He also joins in the robbery. But when members of the gang start shooting at one another, it becomes clear that he is definitely in over his head.