Continuity mistake: The pint of beer seems almost full during the visit to the pub, with Tim's wife. It's suddenly half empty when he drinks it, then almost full again.
Other mistake: At the very beginning of the film, we see Christie commit a murder at the end of the Second World War whilst wearing the uniform of a Special Constable. Christie served during the First World War, and he wears the ribbons of the 1914 or 1914/15 Star, the British War Medal and the Victory Medal on his tunic. Unfortunately, whoever put them on put the bar upside down - they read from left to right VM, BWM, Star.
