I believe you are trying to classify what they bought as something it isn't (ghost shift goods). They legitimately bought the surplus from an authorized retailer.

If you go buy a bunch of Nike shirts from a Nike store they cannot stop you from selling them on eBay or Amazon (at least legally). At best the shoe company could have sued their authorized retailers for the bulk sale if it violated a contract.

Amazon happily complied with an illegal request to restrain trade causing damages to a small company. The lawsuit would have been huge.