 Cowan's television credits include "Judge John Deed", "Ultimate Force", "Jonathan Creek", "Poirot", "Foyle's War", "The Ruby in the Smoke", "Lost in Austen" and the television movie "The Project", 2009 Agatha Christie's Miss Marple 'They Do It With Mirrors' as Wally Hudd.He also appeared in a 2009 commercial for Women's Aid.Cowan has appeared in the films "The Golden Compass", "Happy-Go-Lucky", "The Christmas Miracle of Jonathan Toomey", "Love and Other Disasters", and "Howl".