[Twan]

The chances of looting an item are based on its rarity and I think the same no matter who carried the item. The item you mentioned is an artifact so you should had a big chance of looting it (I think 80%), and probably very bad luck. Note that looting an item if all your present commanders can't equip it is also impossible (so a 2 hander can't be looted if all the remaining commanders have a 1 or 2 hand weapon).