Continuity mistake: After Frank escapes walking on the rooftops, he climbs a balcony and a boat packed with people disappears between shots.
Visible crew/equipment: While Frank is on the rooftops, when Elise stares at him there's a huge crowd of people on the right watching the filming.
Continuity mistake: Foursome dining behind Elise and Tupelo in scene on train: the amount of water in the girl's (in the black dress) glass changes too much too quickly. There isn't enough time in between shots.