Revealing mistake: When Jason climbs onto the rail of the fire escape, it is not attached to the wall - intentionally, it has not broken - but then in another shot, two seconds later, it 'breaks'. It pulls out of a visible hole in the wall, although it was never actually attached and there was no hole before. (00:23:25)
Revealing mistake: There is no snow at all on any surface higher than the second floor of the consulate, except for the sill Bourne is climbing on, and the fire escape.
Revealing mistake: Just as Jason is returning to the car from the train station after dumping the bag in a locker, spectators can be seen watching the filming, which was apparently done on the sly and without consent. Nonetheless, the onlookers did notice the film shoot and followed the actors' actions, who are not doing anything in the scene to draw attention to themselves. Watch the black man to the left of Jason in the background, he follows the scene and his head turns as he watches. Then look behind Marie right after that and there are 2 or 3 people watching as well, in the background. This is very visible and very distracting. (00:50:50)
Revealing mistake: In the night scene where the Professor is driving in the rain to assassinate Womboosi, 2 people are visible in the car when it is shown from the front. Later he states that he always works alone so there is no reason for the other person.