If there is a dispute between you and the RV owner regarding any damage to the RV during the rental trip then security deposit will be on hold till it is resolved.
In case of CruiseAmerica you do not have any choice as their word is likely going to be final. In case of RVShare and Outdoorsy both these companies will try to act a neutral party and follow industry norms to settle the issue amicably. Once the issue is resolved then any excess security deposit after paying the damage will be refunded to the renter.