Character mistake: At the beginning of the film, Matt arrives at Paddington station in West London. He needs to meet his sister who lives in Chelsea - also in West London. However, for some bizarre reason he gets to her via meeting at Bank station - in east London. It makes no sense why he would make such a convoluted journey. Even if as a tourist he simply doesn't know London well enough to make a more efficient journey, his sister - who lives there - would correct him when arranging a meeting point.
Suggested correction: It's possible his sister knew she was going to be in that area anyway so it would be a convenient place for them to meet. There's no mistake here, just something plausible that isn't, and doesn't need to be, explained.