Revealing mistake: When the purser's safe falls through the ceiling, the ceiling metal is far too thin. Bearing in mind also, that the on the other side of the ceiling metal is supposed to be the floor of the next deck up, and that too is a thin flimsy metal, that doesn't even appear that it could support any kind of weight.
Factual error: When they visit "Ireland", presumably the Irish Air Corps aerodrome in Dublin at the time of WWII, all of the staff in the bar at the aerodrome are American servicemen, in neutral Ireland.