eBay seller got ripped off over $1000 from a buyer.3/20/15

I sold a 1 oz.Gold coin on eBay to a buyer for $1000.I shipped the item with signature confirmation and insurance.

The buyer receives and signs for the package as I have proof of signature from USPS.
The buyer claims empty package received.Buyer never attempted to contact me the seller.Buyer automatically opens a eBay case.The eBay case was opened and closed in the buyer's favor within 12 hours.eBay never gave me the seller the right to respond to the case what so ever.eBay's policy states that members are given 3 days to respond.I was never given anytime to respond to the case.eBay didn't follow their policies.
Buyer claims empty package received and automatically wins case.I'm out of the item and the money!Buyer got the cake and ate it too!
I was never given a copy of a police report or a copy of USPS inspector report stating empty package received by eBay.eBay never provided me with any information about the case/claim.
The buyer claims that his USPS mail man wrote on package "refused to sign".If the buyer refused to sign for the package.Why would the USPS post man give the buyer the package without signature confirmation?The buyer claims he refused to sign for the package.He claims he called eBay and eBay told him him on the phone that he must sign for the package in order to be covered under eBay's buyer's protection.Sign for it or else he says!..Ya right like eBay is extorting buyers to sign for packages or else?If a package was empty no one would force me to sign!...

eBay never gave me the right to respond to the case.
I have USPS signature confirmation signed by the buyer that the buyer did in fact sign for the package.

I haven't seen a thing from the buyer's claim.eBay never provided me a thing.

If a buyer received a empty package in the mail.The first thing a buyer would do is contact eBay.eBay then would tell the buyer to call police to obtain a police report of a empty package.The Police will tell the buyer to contact USPS and report this claim to them.USPS will send a USPS inspector to their home to inspect the empty package for any signs of tamper.After USPS inspector findings is complete,USPS will tell the buyer to take the package and the USPS inspector report to the police department so the police can file a police report with that information in the USPS report.
Then,USPS will insert the empty package into a clear shipping bag and return ship the bag to the seller.

I have never received the empty package.Buyer never stated to me that the package was ever inspected by the USPS.eBay nor the buyer ever provided any type of photos or information regarding the case of empty package received.No police report either!

I can't file a insurance claim because,eBay never provided me photos or any information of such buyer claim.I never received the empty package from the buyer to help claim insurance. I've been ripped off by eBay.eBay helped the buyer rip me off over $1000.With the lack of information I have from eBay I filed a insurance claim with eBay and USPS awaiting insurance claim.I paid eBay $25.17 with ship coverage insurance to ship this package.And I got ripped off by eBay.I reported all of this to Ca BBB as well awaiting a answer.What else can I do?