[2][3] Johnston was decommissioned in June that year in which he later studied at the Sydney Technical College and became an associate of the Australian Society of Accountants.
[1] Between 1951 and 1986 Johnston would rise through the ranks of the John Fairfax & Sons to become its chief financial officer and also other motor vehicle manufacturers in Australia, including the precursors to Toyota.
[5][1] Under Johnston's leadership Toyota emerged as the largest car manufacturer in Australia, surpassing both Holden and Ford.
[6] After retiring from Toyota in December 1994, the final year of his life was consumed by consistent bouts of ill health and cancer diagnoses.
[3] Ultimately, following Johnston's death in May 1995, at the age of 70, Prime Minister Paul Keating remarked in a press release that Johnston was a "true captain of Australian industry" and through his actions, had strengthened Australia's economic ties with the emerging markets of Japan and China.