I’d assume from what you’ve said is that the leak was from a pipe within your unit and if this pipe only supplies your unit then you are responsible for the repairs to said pipe. Any damage to the structure would be covered by Strata Insurance policy, and your contents policy should cover the contents damaged in yours and your neighbors unit.
If the pipe supplies more than 1 unit then it is OC responsibility to repair and make good repairs via insurance for all the damage both to the contents and structure. (Strata Insurance might object to covering the contents damage so the OC might be liable for this if you don’t want to claim on your contents insurance)