Revealing mistake: When they leave the caravan park, look at the wheels of the caravan they are set up to rear steer like a truck trailer, rather than a normal caravan. When they exit the park the caravan tilts, giving a good view of the set up underneath.
Revealing mistake: At the end in Paris, the Eiffel Tower is lying on its side with its bottom arches intact showing no signs of damage, as if someone has just pushed it over.
Answer: It must be either a piece of equipment that someone noticed was in the shot, and tried to move out of the way in time. Or some sort of reference marker for Tom Cruise to take a cue from and point his gun at.
Scott Benham