 CONT: At the start of the film when Preston asks Partridge about the  Yeats poetry book he has in his pocket which was taken from the  raid, the book is clearly a relatively thin paperback volume.  However, when Preston confronts Partridge later and accuses him of  being a sense offender, shortly before shooting him, Partridge is  reading the same poetry book he took from the raid, which is now a  much thicker volume. He is also reading it from back to front, or  else he is reading it very slow since the guard at the gate  said,"...hes been coming here for weeks..."