Compulsory management (which is what I assume you mean by “administration”) is one of those “be careful what you wish for” options. Satutory managers don’t have to consult the committee or the owners. They do tend to do things by the book and there have even been allegations of them getting work done at inflated costs by their mates.
A less radical alternative would be to petition NCAT under Section 238 (below) to have this owner permanently removed from the committee. I’m not sure what the burden of evidence for this would be but if you could put togehter a convincing case, with supporting evidence, testimony and stat decs, it might be worth a shot.
In any case the first step would be mediation where the agitator might get a sense that his days were numbered and start to behave.
If you do go down the route of removal of the offending owner from the committee, as I said before, the bar is quite high. I could only find a couple of cases where this was attempted and both failed. In this case (https://www.caselaw.nsw.gov.au/decision/17d6edc72ea4f562136fcef9) the tribunal appointed a strata manager for a year, just to break the cycle of conflict, and didn’t rule on the S. 238 application as the targetted member had already left the committee.
I think the critical factor would be if you could prove that the agitator “engaged in serious misconduct”, especially if you could show how that was a barrier to the smooth running of the strata scheme. If you can show that it had financial implications, so much the better.
238 Orders relating to strata committee and officers
(1) The Tribunal may, on its own motion or on application by an interested person, make any of the following orders—
(a) an order removing a person from a strata committee,
(b) an order prohibiting a strata committee from determining a specified matter and requiring the matter to be determined by resolution of the owners corporation,
(c) an order removing one or more of the officers of an owners corporation from office and from the strata committee.
(2) Without limiting the grounds on which the Tribunal may order the removal from office of a person, the Tribunal may remove a person if it is satisfied that the person has—
(a) failed to comply with this Act or the regulations or the by-laws of the strata scheme, or
(b) failed to exercise due care and diligence, or engaged in serious misconduct, while holding the office.
The opinions offered in these Forum posts and replies are not intended to be taken as legal advice. Readers with serious issues should consult experienced strata lawyers.