It's a disappointingly banal piece, apparently taking a single (though lengthy) anecdote and making it into the whole "interview". Did the interviewer ask any other questions, or did they just think, "Ah, I have a whimsical story about misbehaving cows, what else do I need". I could just be being overly harsh towards the journalist involved, but in the little snippets I've seen of Hardwicke, such as the featurettes on the official website.
Anyone interested in more substantial answers may want to consider popping down to the 2006 Heartland Film Festival, where the film will also be showing on the 22nd October and will be followed up with a Q&A with Hardwicke (hat tip to FilmChat).
The other major piece of news is that an album called "The Nativity Story: Sacred Songs" will be released on the 31st October. Amazon are calling it a soundtrack, but with that name I wonder if it is "songs that inspired the film" type affair. Certainly this film has borrowed their photo-book idea from The Passion, so it wouldn't surprise me if they used this idea as well. Thanks to Queen Spoo for that one. Anyone interested in the soundtrack might be interested in reading Spoo's interview with the composer.