Revealing mistake: Series 3, Episode 5: "Imperfect Strangers". When Ben and Susan are in the car on the way to Manchester you can see the background is superimposed.
The Second Greatest Story Ever Told - S3-E6
Revealing mistake: Second Greatest Story Ever Told: Ben, at the end, has the tooth blacked out and at one point you can just make out a bit of tooth visible.
Continuity mistake: A Handful of Dust: The amount of cereal Ben has in his bowl changes between shots.
Continuity mistake: In one shot, Ben's arms go from beside him, but when the shot changes after Susan has got up off the floor, one of his arms is pointing towards the kitchen and he is clicking his fingers. (00:01:25)
One flew out of the Cuckoo's Nest - S3-E13
Continuity mistake: Nick pulls a pint of Tetly and it's still frothing up to a head when he puts it on the bar. Camera cuts and now the pint has settled completely. Something that normally takes a minute or two.
One flew out of the Cuckoo's Nest - S3-E13
Other mistake: Nick pulls a pint of Tetly on a hand pump. He pulls it once and fills a pint glass. You need to pull the hand pump at least twice before you can get a pint of Tetly.
Revealing mistake: Ding Dong Meraly: When Susan corners Janey in the kitchen to talk about the baby, she slams the kitchen door and the entire set wobbles rather noticeably.
Continuity mistake: Ding Dong Meraly: When the living room is full of Christmas Trees, Ben grabs Nick's neck. Next shot his hands are nowhere near his neck.
Continuity mistake: Ding Dong Meraly: When Nick is asking Ben for the money to set up his drivethrough Santa's grotto, Nick's arms constantly change position depending on the angle. These are instant cuts.
Continuity mistake: Ding Dong Meraly: When Ben first spots the Christmas trees in the living room, his hands are out in front of him. The camera changes and they are now instantly at his side.
Answer: Easy. He could have got the guitar at any point in his life. As for keeping it in the attic? You're not going to throw out a £1000 guitar any time soon.
Ssiscool ★