The issue is that there's huge incentives for vendors to counterfeit and few incentives for stores to deeply spot-check their middle-layer resellers or the stories they're told from wholesale sources, many of whom are in another country (with all the associated barriers of communication, documentation, and even good ol' fashioned "playing the foreign sucker for their money"). When nobody is actually getting hurt, the incentives to make sure everyone is playing by the rules are very low (and the benefits for cheating, i.e. making win-win deals that bring costs down while bringing revenue up for the merchant and some counterfeit outfit at the cost of lost potential sales to the brand owner, are high).
My recommendation would be to treat all stores with a long supply chain as sus until proven otherwise.
