Factual error: In the scene where Ewan McGregor drives to Belmont MA to visit Paul Emmett, he checks the mailbox to see who mail is addressed to. It shows the name Paul Emmett, address, Belmont MA 02324, which is the wrong zip code; it is the zipcode for Bridgewater MA, and Belmont MA should be 02478.
Factual error: Lang refers to 'The Times of London'. A British person talking to other British people, as he is, would always refer to Britain's premier newspaper by its correct title 'The Times'. Only foreigners call it 'The Times of London' to distinguish it from, for example, 'The New York Times' or 'The Times of India'.