How does PayPal Goods & Services protect the seller?

[rugbymarine]

I'm selling a card (on another forum) to someone with zero transactions or references (and minimal overall activity) on that forum. They have a solid eBay history as a buyer and a seller. Their communication has been normal, without any of the usual scam red flags (different email, my brother heard about this from a stranger in a park, etc..)

They've agreed to pay using PayPal Goods & Services, which I prefer.

Let's say the transaction is paid that way, then fast forward a week, they claim:
(a) They didn't receive what they paid for
(b) They received an empty box
(c) They try to reverse the transaction via CC or some other form of buyer protection that PayPal offers.

In those cases, how does using PayPal G & S actually protect the seller? Even using PayPal G & S, are there potential scenarios where the transactions goes south?

I'd love to hear others experiences on this one...