He and his wife the artist Alex Snellgrove own the publishing company Duffy & Snellgrove, which published the first books by Peter Robb (Midnight in Sicily), Ashley Hay (The Secret), John Birmingham (He Died with a Felafel in His Hand) and Rosalie Ham (The Dressmaker).
Other authors included Les Murray, Mungo MacCallum and John Olsen.
Duffy presented ABC Radio National's Counterpoint with Paul Comrie-Thomson[when?].
Set up to provide some balance to the station's left-wing Late Night Live, Counterpoint went on to rate better than its source of inspiration.
[2] He is now writing the Bella Greaves series of crime novels set in the Blue Mountains.