 Shaun berates Ed for calling the creatures zombies (which they are,  of course). This may be referring to the fact that many zombie  movies (including _Night of the Living Dead (1968)_ (qv) and  _Resident Evil (2002)_ (qv)) never mention the word "zombie" at all.  More likely this is a reference to Danny Boyle (qv), director of  _28 Days Later... (2002)_ (qv), and his insistence that it isnt a  zombie movie.