During the scene where they are watching a pirate movie, the Wilhelm scream can be heard. It's impossible since the first recording of the scream was in 1951, many years after this scene take place.
During the New Year Eve's party after Linda's marriage to Christian a song performed by a Russian songwriter Vladimir Vysotsky can be heard in the background. Vladimir Vysotsky was born in 1938 and the song was written in 1967.