Jamison left Sydney for London in 1809, with some of the other mutineers, to safeguard his financial affairs and testify against Bligh at any legal proceedings that might arise as a consequence of the governor's overthrow. He leased a residence in London's fashionable Portman Square but fell ill during 1810. His condition deteriorated and he died on Upper Berkeley Street, Portman Square on 25 January 1811. Jamison's death denied him the opportunity to give evidence at the trial of Major George Johnston, of the New South Wales Corps, who had been a ring leader of the anti-Bligh plot. (Johnston's trial convened in June 1811.)