It comes down to who who owns the gun. Payment alone is not legal transfer of ownership. The seller may purchase insurance, on your behalf, but you still do not own the gun until you get a FFL form filled out and approved. Antiques are different.

I have had two guns with damage in shipment, more that showed up late but that is another shipping problem. In each case the carrier required the shipper to file the claim. Since I had not yet filled out the FFL form and had in fact refused to fill out the FFL form, to accept legal possession of the gun, it was still property of the seller. If you can not get approval on the FFL form you can not become the owner of the gun. I refused to even start the paper work because it was damaged in shipment. Both boxes had been beat to heck in shipment. Both claims were denied right off the start but ended up being paid in the end. I think it is a common thing to deny them and hope you give up. Both claims were paid to the seller not to me. I got a refund in the end but not from the insurance but from the seller.

Other sellers may try to make you deal with everything but I expect safe delivery, in condition as stated in the sale of the item. That has been my experience so far and I hope it never happens again. Some local laws may be different I am sure. I think that is why so many dealer refuse to deal with California sales thinking that the regulations there make safe sales a bigger headache.