Question: Who was a silent film actor in addition to being a director, Christy Cabanne or David Howard?

full_context: Document 1: Howard M. Mitchell: Howard M. Mitchell (December 11, 1883 – October 9, 1958) was an American actor and film director. He appeared in 270 films between 1910 and 1952 and directed 38 silent films between 1915 and 1927.
Document 2: Edward L. Cahn: Edward L. Cahn (February 12, 1899 – August 25, 1963) was an American film director.
Document 3: Howard Hawks: Howard Winchester Hawks (May 30, 1896December 26, 1977) was an American film director, producer and screenwriter of the classic Hollywood era. Critic Leonard Maltin called him "the greatest American director who is not a household name."
Document 4: Abel Gance: Abel Gance (] ; 25 October 188910 November 1981) was a French film director and producer, writer and actor. A pioneer in the theory and practice of montage, he is best known for three major silent films: "J'accuse" (1919), "La Roue" (1923), and the monumental "Napoléon" (1927).
Document 5: Michael Howard (filmmaker): Michael Howard (born Feb 18, 1978) is an American actor, film director, screenwriter, cinematographer, and founder of the film company Invisible Productions.
Document 6: Christy Cabanne: William Christy Cabanne (April 16, 1888 – October 15, 1950) was an American film director, screenwriter and silent film actor.
Document 7: The Sixth Commandment: The Sixth Commandment is a lost 1924 silent film drama directed by Christy Cabanne and starring William Faversham.
Document 8: The Great Secret (serial): The Great Secret is a 1917 silent film adventure serial directed by Christy Cabanne and starring Francis X. Bushman and Beverly Bayne. It was produced independently by Louis B. Mayer and released through Metro Pictures. Mayer's first production credit.
Document 9: Howard Bretherton: Howard Bretherton (13 February 1890, Tacoma, Washington – 12 April 1969, San Diego, California) was an American film director, film editor, and the father of film editor David Bretherton.
Document 10: William K. Howard: William K. Howard (June 16, 1899 – February 21, 1954) was an American film director, writer, and producer. Considered one of Hollywood's leading directors, he directed over 50 films from 1921 to 1946, including "The Thundering Herd" (1925), "The Power and the Glory" (1933), "Fire Over England" (1937), and "Johnny Come Lately" (1943).
Document 11: David Howard (director): David Howard (October 6, 1896 – December 21, 1941) was an American film director. He directed 46 films between 1930 and 1941. He was born as David Paget Davis III in Philadelphia, Pennsylvania and died in Los Angeles, California.
Document 12: Howard Hawks filmography: Howard Hawks (1896–1977) was an American film director who made 46 films (including two uncredited) between 1926 and 1970. He is responsible for classic films in genres ranging from film noir, screwball comedy, crime, science fiction and Western.
Document 13: William Castle: William Castle (April 24, 1914 – May 31, 1977) was an American film director, producer, screenwriter, and actor.
Document 14: David Butler (director): David Butler (December 17, 1894 – June 14, 1979) was an American actor, film director, film producer, screenwriter, and television director.
Document 15: National Red Cross Pageant: National Red Cross Pageant (1917) is an all-star revue silent film, now considered a lost film, directed by Christy Cabanne.
ground_truth: Christy Cabanne