Requesting thread lock. The question has been answered regarding item restoration.
Answer. Nostalrius doesn't recover any lost/sold/deleted/destroyed items unless it matches certain criteria.
Viper wrote:Item refunds Epic raid items can be restored in the case of a server crash/roll-back, providing a message is sent to us which fulfills the following conditions:
Exact date of the raid;
Screenshot of the raid ID;
Screenshot of the loot & Full list of raid members;
Name of the player who received the item.
Regarding deletion warning. When a user attempts to delete/destroy an item with the rarity of rare or above then there's a clear warning that requires user input before the item is deleted. But an user is able to sell any sell-able item without warning to a vendor.