Batutta
Major Contributor
That's a lot of supposition, though. It's definitely a rather large loose end. He couldn't stay on the boat; the sultan of whatever country they were from would be very unhappy. He can't really make his way through France; everyone in French law enforcement should be looking for him. Too big of a point just to say "oh, well." IMHO.
But their escape is not impossible, certainly not for a person with his background. The filmmakers just decided they didn't want to spend time on showing their escape, which I think had less to do with plausibility and more to do with creating a clean emotional catharsis.