Fernando Rey was cast by mistake;
William Friedkin wanted an actor he remembered seeing in
Belle de jour (1967), and the casting director thought it was Fernando Rey - who was hired. Only upon arriving at the airport to meet Rey did Friedkin see that it was not the actor he had been thinking of; he also learned that Rey spoke no French. Once at Rey's hotel (the same one he stays at in the film), Friedkin called the casting director, who realized he had confused Rey's name with that of the correct actor,
Francisco Rabal. Friedkin considered firing Rey, but changed his mind once it was learned that Rabal wasn't available and didn't speak any English, either.
more