J M Sinclair's oft repeated remark that great writers steal derives from a statement generally attributed to T S Eliot that "Good writers borrow, great writers steal".
The rodents of unusual size that feature in the film are called coypu
The movie that Sinclair is screening during his conversation with Liam, in which gunshots are fired, is "Yield to the Night" starring Diana Dors. In this 1956 film noir, a woman exacts revenge upon the rival for her boyfriend's affections who has spitefully spurned him and caused him to commit suicide.