Seems like a pretty clean cut out case. Both buyer (Izwan) and seller (Silverfire) agreed to the exchange of goods (the lens). So why the need to drag and pull other parties into this? The case formerly involves the transaction between buyer and seller so now are you going to blame the supplier or other parties for defective goods sold? So what's next the supplier blame the manufacturer? when does it end?

How does the compensation goes will depends on the ethics of both parties to settle this case, though in Izwan case it didn't NOT involve other parties (e.g. salvator) since neither of them have any relations. READ: Buyer didn't made any form of agreement with salvator whatever directly or indirectly, the liability does not associate him.