Who is Responsible if the Retailer Doesn't Register the Warranty of the Product?
The answer will depend on the policies of the manufacturer involved. If company policy states that registration is the responsibiliy of the retailer, then there may be a claim for breach of contract or negligence against the retailer for out-of-pocket losses.
For example, the following is one company's warranty policy:
Products sold through online auctions, by unauthorized dealers or discount retailers are not eligible for warranty services from Excalibur . To obtain warranty service an original or copy of the sales receipt from the original authorized retailer is required and a completed warranty registration. THEREFORE, YOU SHOULD RETAIN YOUR SALES SLIP OR INVOICE. Excalibur will not replace missing components from any package purchased through an online auction.