I see Sazda's point with the 2 identical items. We've resolved this issue for the future by placing all idenical items in to seperate bid times. If 2 items come up, and the first item only receives only 1 bid, the second item is sharded. Otherwise loot continues as normal treating each peice as it's own.
Last night if the 2 items had been done seperatly say;
Item 1
Sazda 15
Lamp 15
One of them would have gotten it for 16, after a /roll
Item 2
Sazda 10
Lamp (Got Previous Item)
Sazda would have been charged 11
This is assuming no backend deals where only Lamp bids on Item 1 and Sazda only bids on item 2.