The last time I had to queue for passport control in WAW, it turned out that the clueless pax immediately in front of me was actually travelling to a Schengen country. When the border staff told her that she needed to exit the queue and go to her gate in the Schengen area she got flustered and refused to accept it. They were actually trying to help her... there was no way she would be allowed through anyway and she needed to go to the correct gate (obviously not on the far side of passport control). She was there for several minutes (seemed like an eternity) until she finally realised she wasn't getting through and walked away. I really had a hard time biting my lip while she was standing there but I figured that starting a shouting match right in front of passport control wouldn't be a smart play.