Well there doesn't have to be damage to the package to be internal damage to sensitive electronic equipment. I once had a power conditioner arrive at a buyer's damaged. The only visable sign of damage was a cracked glass meter cover. The power conditioner did not function either. The box looked perfect. Fed Ex, the shipper, investigated and paid off the claim saying the damage could have come from a "flat drop". You can drop a box X feet and have it land perfectly flat, thereby not damaging the box itself. That doesn't mean it is healthy for what is inside the box.
If you have any intention of filing a claim, DO NOT have the cartridge shipped back to you. Once the cartridge has been shipped again, the insurance you purchased for the initial shipment is voided. You need to contact the carrier and have them inspect the "damage" at the buyer's residence. Any decent buyer should assist you with a claim if you were kind enough to refund the money.
I don't know offhand if the XV-1s has a serial number. I guess I just assumed it, because many high end cartridges do have serail numbers, like the ZYX 4-D that I'll be shipping out this week.