They probably deal in stolen goods somewhat frequently, but even if you could trust whether the sale was legal Hobby Lobby needed to ensure the import was legal.
If you are buying something from another country, you are responsible for ensuring it is legal to ship into your country. A seller doesn't need to know every countries laws.
That said, knowingly buying counterfeits is illegal. If you have good reason to suspect it's counterfeit before buying, you could be charged.