I'm sorry to inform you, that if it got beat up enough to actually come out it should have been packed better or in a better/larger box, that is unless it had been skewered by a forklift or run over...
I wrote a neat FAQ on ebay on how to properly package things to take most abuse usps or UPS can dish out. You should ask your customer for a copy of the "note" and a photo of the box. If you are satisfied it's legit, than refund them or replace the item and chalk it up to a learning experience.
If you refund your customer and make it right than you'll have about an 80% chance you'll probably keep your customer and not get screwed over by them, about 5% of the time your customer will be mad and jump off the deep end and claim a half truth that you sent an empty box.
If they jump off the deep end, neg you and flame you on the net there isn't much point of refunding unless they will win anyway such as a payment by CC or PP. In that case refund anyway to save time and hassles.
None of the options are correct there except the last one which is partially correct. A seller has the job of always offering insurance on everything they sell. A buyer has the responsibility to purchase insurance on a package if they feel it is fragile or very valuable. If the seller feels that the item is valuable, they should require the buyer to purchase insurance. The seller has the responsibility to package the item to the best of their abilities, this mean that they package it with plenty of packaging and make sure that everything is secure before they send it. At this case, if the package gets damaged in transit, it is the sellers job to deal with all of the insurance claim paperwork.
If the seller does not offer insurance, then any damage or non receipt of the package is their responsibility and they must replace it. However, the seller has the right to charge the buyer shipping to have the item replaced.
If the item is damaged do to poor packing, then it is the sellers responsibility to replace the package or damaged items at their expense.
Don't know in U.S., but here couriers are "never responsible" for damages due to shipments, cause they always claim that the cause was "insufficent package" (if you send something inside a steel safe, and it arrives damaged, for the courier it's always insufficent packaged, LOL )
Seriously speaking, i think it's matter of see before how the item was sent, you don't think ?
That what i mean is ..... if i send you a driver, LD or anything other just slipped in a multiball envelope (or anything you call those all bubbles envelopes), and just hope that it arrives less than pulverized (LOL), then the responsability of the damage is mine, cause i made nothing for prevent it ..... if instead i send it, as example as i do usually, inside an antistatic bag, then wrapped in multiball foil, encased inside a custom made paperboard block, then wrapped and at the end slipped in the envelope, i honestly think the responsability is not mine at all, cause i've done all that i can do for try to avoid damage, and if some of the couriers jumped on my envelope, or maybe just carried it around in the truck under a 500 Kg wooden box, sure i can't humanly do anything for prevent it, right ?
Then, about insurance, it's always difficult , at least here, get them paying for their mistakes ..... as example, if anytime you get a package, you don't write clearly on the delivery document that you accept it "with reserve to check weight and content" , they automatically assume that you agreed to receive it independently from the condition of the content, and all the responsability is considered automatically your so the insurance don't pay you anything, also if broken, without this indication near your signature.