When getting back from their tsunami adventure, Marie and Didier are picked up by a Mercedes-Benz S-Class (model W221) at the airport. However, the W221 was unveiled at the Frankfurt Motor show in the autumn of 2005 and wasn't in production until the beginning of 2006, almost a year after the Indian Ocean tsunami. Moreover, the model in the movie is the face-lift version launched in 2009 as MY2010 (check the LED taillights).
When Marie visits the hospice to get the information on near-death experiences, the wallpaper on the receptionist's computer shows a Windows 7 image (icebergs on the shore) rather than one from Windows XP, which one would expect for a movie set in 2005.
After George speaks to the receptionist at the hotel where Marie is staying, the receptionist resumes typing. However, nothing moves or changes on her computer monitor, which is in full view to the audience.
Throughout the film, it is apparent that Marcus is played by two boys. In many scenes, he clearly has his left ear pierced (although no earring is worn, the hole is very distinctive). In other shots, most notably, during the "subway/underground" scene, he has no piercing.
When Marie goes to the clinic to Switzerland, the mountain road is not in Switzerland but in France. The security sticks along the roads are French ones (white and red). The Swiss ones are white and black.
The Tube station where Markus narrowly misses a terrorist bombing is incorrectly identified as Charing Cross Station. None of the July 7 bombings took place anywhere near Charing Cross. The external shot of the station was taken of the Liverpool Street station where one of the bombs actually did explode on a train which had just left the station. The sign on the exterior was digitally altered to Charing Cross.
Marie and Didier are eating at a Paris restaurant on the evening following the London attacks: 7 July 2005. It is pitch black outside. On that date in Paris, civil twilight ended at 10:38 pm (i.e. the sky turned truly black at that time). That late in the evening, diners at a Paris restaurant would not be mid-meal - restaurants close up around 10:30 or 11 pm at the very latest.
When Jason is hit by the Mercedes van, there is a shot from inside the car Jason's body is thrown onto showing him cracking the windshield. *** The view is not from inside the Mercedes van. This can be clearly seen as the camera pans away from the twins and the black car next to them has a cracked windshield. ***