[1] McMillan has had many roles in the Northern Synod and associated organisations: accountant, operations manager, general manager of the Arnhem Land Progress Association (ALPA) - now the Arnhem Land Progress Aboriginal Corporation, pastor, cultural awareness trainer, resource worker, community developer, and Moderator.
[1] After living and working in the Northern Territory for some time, a man McMillan knew adopted him as his brother in the Gupapuyngu clan of the Yolngu nation with the skin name bulany meaning red kangaroo.
Djiniyini Gondarra, for 12 years through the period after the High Court’s Mabo case decision established native title.
McMillan was involved in researching the claimants' situations, and making trips to Canberra to assist Gondarra and others as they gave their input on the drafting of the Native Title Act under the Prime Minister of Australia, Paul Keating.
[2][3] He started his address to the installation service with the words, in the Yolŋu language, “Bala limurr roŋyirr ŋorraŋgitjlil” – “Let us return to the white ashes of the fire”, an allusion to the Holy Spirit.