Continuity mistake: In the ending scene with Daniel and Eli, Daniel starts yelling at Eli as Eli is running down the bowling alley. As Daniel is throwing bowling balls at Eli, the first ball is thrown down the left lane, hits Eli in the foot and ends up in the right lane - no pins have fallen. The second ball is thrown down the left lane and is a gutter ball - again no pins have fallen. The third ball is thrown into the right lane, hits a bucket and presumably hits no pins. However, as Daniel is chasing Eli behind the bowling alley you can see that the left lane now shows only 2 pins still standing.
Question: Regarding Paul and Eli. Are they actually twin brothers or is Paul an figment of Eli's imagination and Eli schizophrenic? As far as I remember Paul is only mentioned three times. At the beginning when he meets Daniel, when Eli attacks his father (and says 'you are as stupid as Paul!' and at the end, when Daniel mentions him. Are there any other bits I've missed? Or is it left open to interpretation?