At about 40 minutes the helicopter used (Bell 47J-2 s/n 1850 registration N73202) had a United States registration number. France registrations begin with F and then a series of more letters (F-XXX for example). Beside that it would be more likely that an Aerospatiale SA-316 Alouette III would be used which is built in France.
In Act III, when Napoleon throws the Thrush agent against the wall, we see an adjoining wall tipping over, obviously part of a very flimsy set.