In my opinion you reversed the way you should have built this bow. Hickory is stronger in tensile strength and thus should have been the backing. By adding another backing to the red oak you may jeopardize the hickory belly adding to the amount of set.
Each wood used for bow building has different strengths and weaknesses. To maximize the success rate of building wood bows you should utilize the strengths of the wood in its favor and minimize the weaknesses.
A cloth backing will not prevent a bow from breaking. It will give you a bit of security but it is not a miracle cure.