'Jeffrey Hunter' left production in Spain when the producers ran out of money for the cast and crew. He returned to the U.S., where he died unexpectedly. The film was later finished without him.
Jeffrey Hunter suffered face lacerations and powder burns on the set of the movie in the scene of the shootout between the two cars. This was due to an explosion that took place, the effects of which it is suspected may have caused him to fall months later down a flight of stairs back at his home in California, leading to a fatal brain hemorrhage.