Supposing the situation that a non-dealer ships a firearm to a buyer's FFL (dealer), and that, for whatever reason (failed to pass, chooses to return, never shows up!) the firearm is still the buyer's property, correct? After all it is legal for individuals to sell firearms directly to other individuals (has that law changed?) the difference is the legal requirement to "transfer" the firearm since it was shipped and not a face-to-face transaction. The FFL is not the seller, the firearm is never his property. Does the law prevent the FFL from returning the firearm to the seller/shipper directly?
I've had firearms returned from consignment arrangements without the need for an FFL transfer, after all the firearm is my property.