The German soldier's submachine gun was not able to fire at the start of the execution scene as it was not cocked. The piston was in its forward position making firing impossible.
The movie implies that the earthquake that devastated Cephallonia after World War II occurred in 1947. It was actually in 1953. At the end of the credits, the movie is dedicated to the memory of those who died in the post-war earthquake of 1953. The DVD commentary also mentions the correct date.