Dang. Too late to be thumbing on this smartphone.
If there are books with shoe prints on them, I think it's more likely that the packing people at the printers did it. The books would have been shipped to Amazon from the printer. I can see Amazon employees not noticing the damage or not caring.
Vaseline on the books doesn't make sense to me. As I said earlier, the packers would't have time to do it, and if the books had been greased up earlier, it would have been reported because of the problem of transfer to other products and getting it on the conveyer belt.