Mr Mowbray retired in 2008, after serving for four years on the Federal Magistrates Court (now the Federal Circuit Court of Australia). Prior to this Mr Mowbray served on the Administrative Appeals Tribunal after working in the position of General Counsel (Immigration) with the Australian Government Solicitor for eight years. His early years were spent in various legal positions with the Commonwealth Government.
Mr Mowbray was the Presiding Member of the Australian Wine Industry Code Administration Committee, was President of the Weston Creek Cricket Club, and remains a Member of the National Appeal Panel of the Uniting Church in Australia.
In October 2016, Mr Mowbray was appointed as a Member of the Defence Honours and Awards Appeals Tribunal, for a period of three years, having earlier served as an acting Member.