unfortunately we do not recompensate players for items lost due disconnects, rollbacks or looting mistakes. The only exception to this is boss loot from raids.
I won't understand your discrimination, that is you want to tell if I beat out http://db.valkyrie-wow.org/?item=11684 and through your fault I will lose it, it is normal? My opinion or you give everything that was lost, up to tooth from a panther (invaluable in fact) or don't give anything...!!!