But that is exactly what is happening at the Venice film festival, as The Journey receives its world premiere, with Timothy Spall playing Paisley and Colm Meaney playing McGuinness.
Neither unionist nor republican side has been permitted to screen or indeed veto any part of the film, Hamm says.
The Paisley side said: ‘Oh they got on fine, they were joking and laughing right from the start.’
Hamm says: “Paisley and McGuinness not only had a friendship but also a semi-political relationship of need.