[mehrdadn]

I mean at that point when the post office agrees they had the package, they literally cannot logically blame you, because you could not have had any fault in this decision. What else were you supposed to do, fly over and hand it over to them in person? The onus can only logically be on the receiver to make sure they get the package the post office delivers, not on you.

I understand the trouble starts when there's plausible deniability and no witness around. How do you prove they shipped rocks? How do they prove they didn't? At that point it really could be either person's fault, and their policy seems to be to blame it on the seller. That's what people mean when they say eBay "always" sides with the buyer. They don't mean that this is literally true even when it clearly doesn't make sense.