Having himself witnessed the heavy cruiser firing on the Japanese minisub M-24 in Sydney Harbour on 1 June 1942, Dulhunty developed a lifelong fascination with the event which culminated in publication of his forensic analysis in 2009 concluding that the sinking of during that encounter was not, as the official account would have it, to a torpedo fired by the Japanese submarine but, rather, a five-inch shell from one of the guns of the "Chicago". Dulhunty's account attracted press interest at the time. Dulhunty was the pilot of the seaplane which re-enacted the 30 May 1992 Japanese reconnaissance flight which preceded the attack on its 50th anniversary and he was instrumental in the original Yokosuka E14Y1 "Glen" floatplane's rediscovery in 1994.