There was a real historian named Filip and his widow claimed the series was making fun of him, despite both writer and director claiming they never knew about his existence. The widow went to court and won. The production had to change the name of the character - in the series that had already been aired. For re-runs, they did it with blunt re-dubbing of every word "Filip" with "Richard", making it very obvious.
Jaromír Hanzlík was considered for the part of Dr. Jacques Michell, eventually played by Jirí Datel Novotný.
Petr Nározný and Pavel Zednícek were considered for the part of father Bernau, eventually played by Eugen Jegorov.
Zora Jandová was considered for the part of Emilia Fernandez, eventually played by Dagmar Patrasová.