The young man with beard, curly hair and glasses behind Laura when she talks to the camera is not Álex de la Iglesia but 'Francis Aguilar'. An Almeria-born director of short movies ("Zombeach"), he joined the crew of 800 balas and became a friend of de la Iglesia. They look so much alike that they decided to give him a cameo role to fool the audience.
Director Álex de la Iglesia wanted Clint Eastwood to play himself in the film. He even offered to move to Los Angeles to shoot Eastwood's part. Eastwood, who was then working on the production of Mystic River (2003), was forced to turn down the offer.