Factual error: The train to London that everyone gets on is a French TGV. The TGV doesn't run through the Channel Tunnel, only the Eurostar trains do.
Factual error: When Joshua and Il-sang Lee rush to the hotel to search for the stamps, they are in Clinancourt, which is a North suburb of Paris. In the next scene, we see them leaping into the train, and the station is 'Pyramides', which is a station in the center of Paris. They would have needed a 30 minutes ride and at least one train to change to get from Clinancourt to Pyramides.
Factual error: The first scenes outside the hotel where Regina is staying were filmed in some area very typical of the 8th arrondissement of Paris. In the end, when Joshua and Il-sang Lee rush to that hotel to get the stamps, they get off at Chatelet, which is in the 1st arrondissement. A few scenes later, they rush out of the hotel, run for less than a minute and find themselves in a desert street which can exist neither in the 8th nor in the 1st arrondissement. It was certainly a street in some remote Northern area of Paris.
