Audio problem: When Charisma knocks on Kevin's houseboat, he says "It's Me, Les!" but his mouth is not moving at all.
Episode #4.7 - S4-E7
Factual error: In this episode Blackwall Station is shown as a London Underground tube station. Blackwall Station is a Docklands Light Rail (DLR) station. Also look at the destination sign on the front of the train, which reads 'THAMES LINE', No such line/station exists on the London Underground.