I am in the ACT but I am inclined to agree that if a unit owner (party A) has damaged the property of the owners corporation (party B), then the OC can seek reparation for the costs of rectifying the damage. It does not seem relevant to me for this argument that party A is a member of the OC. Party A and party B are separate legal entities. This would be the same if the damage to the common property were caused by a ‘party A’ who was entirely unrelated to the OC?
For an alternative argument, I assume you would have a bylaw along the lines of ‘A unit owner must not unreasonably interfere with the reasonable use and enjoyment of the common property by other residents.’ Damaging the common property would be an unreasonable interference, I would have thought, and this could be used to invoke the dispute resolution mechanisms associated with breaching a bylaw.