The OC is liable in the first instance because of its legal duty to maintain and repair common property (even though they are doing their best to effect this). They then need to claim against the insurer. Look at it this way, if the insurer refuses to pay, the OC still has to stump up so they may as well pay now and claim later. Better to keep relations on a cordial footing and do the right thing rather than find excuses so they don't have to dip into their funds. And don't forget, oit's the home owner who's really suffering.