He was not credited for editing Erich Von Stroheim's Blind Husbands (1919), The Devil's Pass Key (1920), and the 18-reel version of Greed (1924).

He edited several films for Rex Ingram, notably Hearts Are Trumps (1920), The Four Horsemen of the Apocalypse (1921), and The Prisoner of Zenda (1922).

Whytock began his lengthy permanent collaboration with producer Edward Small in 1933 as editor for I Cover the Waterfront.

Whytock was credited as producer of Small's The Return of Monte Cristo (1946), The Black Arrow (1948), Walk a Crooked Mile (1948), and The Steel Lady (1953).

With Small's Monkey on My Back (1957), Whytock began editing a number of Robert E. Kent's film productions.