QuoteJonathan Nolan: He [Batman] has this one rule, as the Joker says in The Dark Knight. But he does wind up breaking it. Does he break it in the third film?
Christopher Nolan: He breaks it in...
Jonathan Nolan: ...the first two.
Source: http://books.google.com.au/books?id=uwV8rddtKRgC&pg=PR8&dq=But+he+does+wind+up+breaking+it.&hl=en&sa=X&ei