Continuity mistake: When Ben is correcting his cards, his hands constantly move.
While You Weren't Sleeping - S5-E9
Continuity mistake: In this episode Ben's bedroom window is to open towards some grassland with no houses opposite. However, in Season 2, Episode 4, Ben is by a neighbour across the street.
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 ★