Could I suggest to your visitor that if he is about to watch a film made from a beloved book, he might look at some websites that give information about the adaptation, to help prepare himself for the changes that will be inevitable?
The sister site Narniaweb, specialising in the books and the movies being made by Walden Media (note, not Disney), has four and a half years worth of news, information, interviews and announcements on these very topics.
I am sorry that your visitor did not find the changes in the book-to-screen process easy to cope with. Knowing there would be some plot changes (eg to avoid half a book worth of back story and walking through forests) might have been useful to him.