There are multiple discrepancies between the exterior shots of the Plaid Cat pub and the interior scenes, including the shootout. From the inside, a brick wall can be seen outside some of the pub's windows, but there were no brick-walled buildings shown in the establishing exterior shots. Outside another window, a city skyline is visible, but the pub is supposed to be in the countryside and the establishing shot showed only one other house and trees in the vicinity. Finally, when Charlie and Chris exit the pub, as seen from the inside, there is a brick wall outside the entrance door even though the establishing exterior shot showed only a small yard with a walkway leading all the way to the door.
During the brawl in the apartment, the stunt double's bald cap is clearly coming loose.