usually composite airframes are far more tolerant of damge than traditional metal frames, dropping a weight on a composite panel will puncture/crush and delaminate around the impact point, such damage will not cause much residual stresses elswhere as the damage relieves the stress as the fibres and resins are usually broken. wheras metal will stretch, and change its properties permenently not just at the damge point but elsewhere. composite panels have quite a bit of stress resitance to them and the panel will flex/stretch or whatever, but will most likely return to its original state with little or no damage.
a weak point of composits is they dont like water ingress or oil contamination, oil wont effect the undamaged panel, but if it is damaged, it can make repairs very difficult indeed, but water will freeze and expand, expanding the area of damage if it gets into a panel.
the main difficulty at the moment is NDT, to find delaminations or internal damage, but in my experience with composites in the RAAF,NAVY and now Army aiviation sector, is that the damage is hard to find because there is rarely and damage to be found that is not already visible by microcracking of the resin matrix.