Gerda tells Bodie to turn left at one point - but he actually turns right!
When Bodie stops to buy three ice-creams, they have clearly been prepared before he has even asked for them! Lewis ad-libs "That was quick!".
When Bodie is trying to list the counties of East Anglia, Cowley interrupts with "Lincolnshire, Suffolk, Norfolk and Essex". No part of Lincolnshire is in East Anglia, and Essex is also not usually considered part of East Anglia. East Anglia consists of Norfolk, Suffolk and Cambridgeshire.