If they're not genuine, these things are absolutely remarkable forgeries. Indistinguishable.

I mentioned the mixing of inventories, but as I've said, I've purchased literally tens of thousands of dollars worth of items from Amazon. I average about 1.5 orders per week over the past decade, and I've never received an item that I doubted the legitimacy of. Furthermore, after some research it seems that Amazon does not mix their own inventory with third-party sellers inventory; they only mix third-party seller inventory when the seller opts into having their inventory mixed.