In the scene at the start of the episode, Nesbitt's jeans are muddy from being in a field, but in the following scene(s) they are clean.
At the sports club, the union flag nearest the steps is upside down.
The World Chemicals Sports and Social Club signboard misspells the word 'secretary' as 'secretery'.
When Biggs arrives at the reservoir and checks his gun, he pulls the slide back twice. If it had rounds in the magazine the first time would have chambered the round, the second would have ejected it and chambered a second round. No first round is seen being ejected.