Book sold as 'New' from Amazon, had an invoice inside as previously sold

Thought this was interesting in light of the recent submission "Amazon allegedly resells damaged books"[1]

[1] https://news.ycombinator.com/item?id=38818578

This would be a 3rd party seller lying/erroring about the books origin. They should return it saying product not as advertised (I don't remember the options).