Ross Hill (who plays Matt in the movie) was the adopted son of Terence Hill and his American wife Lori Hill. In 1987, after filming Renegade, he was supposed to play Billy the Kid siding again with his father Terence Hill (playing Lucky Luke), but unfortunately, they had to shoot the film without Ross. He died in a car accident on January 30, 1990 when he was only sixteen years old, together with a friend, Kevin. The Lucky Luke film is indeed dedicated to Ross and Kevin.