There is no explanation for why there is a horse on the workers desk during the Jenkins office scene.
Jimmy Guinness is based on a real person and a true story.
Robert Harrison was initially cast as the voice of Danny McGuire but withdrew due to other commitments. He was replaced by Duncan Airlie James who was meant to play the mugger in the film.
The majority of the filming took place in November/December 2012 at the end of the autumn season. The crew spent a couple of days trying to find shots of trees which weren't dead.