In the US, products liability law places responsibility for defective products on all commercial participants in the chain, from manufacturer to the final retail seller.
It doesn't matter whether they're involved in any QC at all; it is sufficient that they're selling a product for profit.
Right, but in this case several parties will get out because they are not part of the chain because amazon did not carefully preserve the full chain. Amazon will be liable to the entirely of the chain not just a part because they didn't track the full train on each product.
