Revealing mistake: When Del is trying to sell those hooky toy dogs, there are some shots of the policeman walking across the street. The same clip of that policeman is played twice, only one is longer than the other (note a grey-haired man walk across the screen twice).
Continuity mistake: When Del is escaping in the van, there is a view from the side of the van and the door is almost completely shut. But in the next shot, which is a direct view of the back of the van, the door is wide open, allowing space for the toy dogs to fall out of the suitcase and onto the road.
Audio problem: When Del, Rodney and Grandad are in the cottage, Del is scared to open the door. Rodney says "Well go on then Del, there's nothing to be frightened of now." There is a shot from behind Rodney when he begins to say this. Look closely at Rodney's mouth when he starts to say this; his lips aren't moving.
Plot hole: Del says that Rodney needs to sort his priorities out about being Chairman of the Housing Committee or working the pitch. However Rodney never tells Del he is chairman (he is made chairman at the meeting in the morning and goes to find Del after the meeting as shown by the same clothes, and Del asking where he was).