Well, the only thing we can be for certain is that the "Mystery Force" is not the lost patrol of the French Foreign Legion. They would have surrendered by now.
Don't know much about the history of the Foreign Legion, do we?
Run a search on "Camerone."
It does say a lot about the French that the unit in their military that inspires the kind of fear and mystique which are commonplace to our Rangers, Airbourne and the British and Australian SAS is made up entirely of non-Frenchmen.