When Bodie and Doyle are stopped by the police on the first occasion (for speeding), they pull up opposite a row of houses. When they drive off again, they are opposite a parade of shops instead.
At around 46 minutes in, either Bodie or Doyle attaches a stick-on microphone to the body of a telephone unit. Surely, this should have been stuck on to the earpiece end of the handset to pick up the vibrations of the speaker.
When Bodie and Doyle are hiding in the gasworks there's a shot of a policeman with a snub nose revolver and you can see there's no bullets in the chamber,
When Bodie and Doyle are unloading boxes from the car, the shape of Martin Shaw's radio microphone pack is clearly visible in his right rear jeans pocket.
Assuming that this episode is set in the Midlands (as is implied by a reference to Derby as being nearby) there is a shot of a Green Line coach in one scene early on. Green Line routes have only ever operated in the south-east of England.