it does work with an empty package but it just goes to another address. So the seller doesn't get any package. If the seller were to get an empty package they would have some proof to show ebay and so the fraud would be harder to stop.
What? Think about it for a second, what proof would they have?
The trick described in the article just improves upon it slightly by making the seller think that royal mail lost the package. There's no dependence on this trick though, the scam works 100% of the time even if the seller receives an empty box.
Ebay will always believe a "hey my box was empty", no matter your account history. They'll just ban your account at some point.
At first glance the empty box seems pretty meaningless, it certainly won't win a dispute for the seller.
I guess you're right though, now the seller won't even realize that they're getting scammed and won't report the buyer account to ebay.
This is just a cost of doing business. Really sucks for amateur sellers though.
If the scammer is in the UK, there's always small claims court. I'm not even from the UK, and I got a scamming seller from there to refund me by just threatening to make a claim.