Question: What did Seth Holt do that Paul Powell did not?

Context paragraphs:
Blood from the Mummy's Tomb: Blood from the Mummy's Tomb is a 1971 British film starring Andrew Keir, Valerie Leon, and James Villiers.  This was director Seth Holt's final film, and was loosely adapted from Bram Stoker's novel "The Jewel of Seven Stars".  The film was released as the support feature to "Dr. Jekyll and Sister Hyde".  Another film based on Stoker's "The Jewel of Seven Stars", "The Awakening", was released in 1980.

Paul Powell (director): Paul Mahlon Powell (September 6, 1881 – July 2, 1944) was an American journalist, director, producer, screenwriter, and actor.  Powell was most active during the silent film era and is best known for directing Mary Pickford in "Pollyanna" (1920).

Danger Route: Danger Route is a 1967 British spy film directed by Seth Holt for Amicus Productions and starring Richard Johnson as Jonas Wilde, Carol Lynley and Barbara Bouchet.  It was based on Andrew York's 1966 novel "The Eliminator" that was the working title of the film.  The film was released in the United States as a double feature with "Attack on the Iron Coast".

Taste of Fear: Taste of Fear (US title: Scream of Fear) is a 1961 British thriller film directed by Seth Holt, shot in black-and-white by Douglas Slocombe, and released by Hammer Films.  The film stars Susan Strasberg, Ronald Lewis, Ann Todd, and Christopher Lee, the latter, one of Hammer's most bankable stars, in a supporting role.

The Nanny (1965 film): The Nanny is a 1965 British suspense film directed by Seth Holt and starring Bette Davis, Wendy Craig and Jill Bennett.  Davis appears as a supposedly devoted nanny caring for a 10-year-old boy recently discharged from a home for disturbed children.  It is based on the novel of the same name by Evelyn Piper (a pseudonym for Merriam Modell), and the film was scored by Richard Rodney Bennett.  The film was made by Hammer Film Productions at Elstree Studios.

Seth Holt: Seth Holt (1923, Palestine – 14 February 1971, London) was a British film director, producer and editor.  His films are characterized by their tense atmosphere and suspense, as well as their striking visual style.  In the 1960s, "Movie" magazine championed Holt as one of the finest talents working in the British film industry, although his output was notably sparse.

Her Market Value: Her Market Value is a 1925 American silent melodrama film directed by Paul Powell and starring Agnes Ayres.  Powell produced the picture and distributed through Producers Distributing Corporation.  This feature is extant at UCLA Film and Television Archive.

Hell-to-Pay Austin: Hell-to-Pay Austin is a 1916 American silent comedy-drama film directed by Paul Powell and starring Wilfred Lucas in the title role, along with Bessie Love, Eugene Pallette and Mary Alden.  It was accompanied by the Charles Chaplin short comedy "One A.M." in some theaters during its initial theatrical release.

Nowhere to Go (1958 film): Nowhere to Go is a 1958 British crime film directed by Seth Holt, his directorial debut.  It stars George Nader, Maggie Smith (receiving her first screen credit), Bernard Lee, Harry H. Corbett and Lionel Jeffries.  After a criminal escapes from jail, his attempts to recover his stashed loot end in failure, as he is shunned by the criminal community and hunted down by the police.

Station Six-Sahara: Station Six-Sahara is a 1962 British-West German international co-production drama film directed by Seth Holt and starring Carroll Baker, Peter van Eyck and Ian Bannen.  It is a remake of the 1938 film "S.O.S. Sahara", which had been based on a play by Jean Martet.

Supporting paragraphs: Seth Holt Paul Powell (director)
Answer: British film director