Visible crew/equipment: The stunt man driving the car as the Jackal enters France looks nothing like Edward Fox. His hair isn't even the same colour.
Character mistake: When the false passport application is found, they say that the passport was mailed on Jul 14. When Lebel tell the Minister about the passport, he says that it was issued on Jul 30.
Continuity mistake: The first time we see the beautiful Alfa Romeo Spider, the registration plate at the end of the car says GE1761, without a space between GE and 17. The next time we see the car, when he practices shooting in the the woods, the plate says GE 1761 with a huge space between GE and 17.
Other mistake: The Jackal goes out into a field to test his gun and adjust the sights. But the gun is then dismantled again, so the adjustments are irrelevant.
Answer: He would have just slipped away into the crowd, probably with some minor alteration to his appearance. He was a master of disguise and no one knew his real identity or what he looked like.
raywest ★