@Sir Humphrey said:
If it was just an ordinary tree and there was no reason to suspect that it presented any more risk than any other ordinary tree, then I would suggest that the OC is not liable if someone parks under it. It’s just bad luck that a branch fell on the car. That a branch fell and did some damage is not the OC’s fault so liability insurance would not cover it.
This is my understanding also. Unless it could be shown that the tree was in a dangerous or unhealthy state, falling branches and even falling trees due to a storm are classed as an “Act of God” or a “natural causes” type of event.
The tree owner would be unlikely to be liable.
Insurance cover in such cases usually becomes the responsibility of the owner of the damaged property. So each strata in this case should be covered by their own building insurance for any damage done to their own common property or to their own lot owners’ fixtures and fittings. Unfortunately a car is not common property or a lot fixture or fitting.