Unlawful building work - Show cause notice, class 2 units.

My friend has a pre 1960 class 2, two story block of 6 units on the Gold coast.
He wanted to put gyprock over the asbestos walls and ceiling to help with sound reduction but the tradesman talked him into ripping out the asbestos, so he replaced it with two layers of fyrchek in only two of the units. He nearly got into trouble with the asbestos, but it worked out ok.
But now someone has put in a complaint to the council and he has been given a show cause notice for not getting building approval and not getting it certified as fire safe.
Apparently he has to tear it all apart and start again and do the whole six units.
Someone said Section 61 might be the way to get around it.
Does anyone know anything about this or had any previous experience?

BUILDING ACT 1975 - SECT 61
61 Alterations to safe existing work may be approved on basis of earlier building assessment provisions
(2) The building certifier may carry out building assessment work for the application on the basis that the building work is to be carried out under the earlier building assessment provisions.