If someone's lying to us, then it's rare that we know that they're lying to us. It's only in bad films that you recognize immediately that an actor's playing in such a way that you can see that he's lying, and that's simply dumb. But to reach that, it requires that you make a film in such a way that a spectator feels compelled to find his own explanation. You want to lead the spectator to find his own interpretation. To ask questions rather than provide all of the answers. Doing that leads to open endings and open dramaturgy.