Art had a long-running dispute with Abraham Morris (or Morrison) of Hanover Hall, who was Sheriff of Cork ("dirty treacherous Morris", ""Morris ghránna an fhill""). Morris, for reasons of personal enmity, vigorously attempted to enforce these laws. The dispute came to a head in 1773 when Morris offered Art five pounds for his horse; according to the Penal Laws, Catholics were proscribed from owning horses worth more than five pounds. Art refused, and went on the run. Morris was able to use his position as a Protestant, and as sheriff, to have Ó Laoghaire outlawed. A price of 20 guineas was put on his head. Once proclaimed an outlaw, he could be shot at sight quite legally. Ó Laoghaire attempted and failed to ambush Morris at Millstreet and soon after was shot at Carraig an Ime. His mare raced into Rathleigh, riderless, soaked in blood. Eibhlín Dubh mounted the mare and galloped back to Carraig an Ime, where she found Art's body.