The transfer of ownership has been made to the dealer. It is an aquisition in his log book. To make a disposition to anyone that is a nonlicensee including the person that originally sent the firearm to the FFL requires either a 4473 & NICS check in person or shipment to an FFL for transfer to that person if out/state.
A nonlicensee may be 'selling' the gun as far as collecting money for it,,but regs do not allow you as a nonlicensee to actually sell, give, ship, etc a firearm to another nonlicensee in another state. This is the whole reason for sending it to the FFL. You transfer it to the FFL. The FFL legally sells it to the nonlicensee in that other state.
There should be no entry in the A&D book on the disposition side to a non-licensee that does not also have a 4473/NICS check with it. That includes returning a rejected firearm sent for transfer to a buyer. The only place you can log "Returned to owner" w/o haveing a 4473/NICS or an FFL on file is a gunsmithing transaction.
Same rule applys when returning a consigned gun that did not sell and is returned to the original owner,or returning a pawned firearm to it's owner. 4473/Nics checks are a must or ship to an FFL.
A gun sent for value assessment is considered 'gunsmithing' because no change of ownership is assumed in the dealing. Therefore the gun can be sent directly back to the original owner.
When a dealer makes a simple transfer it is both an 'aquisition of a firearm' & a 'disposition/sale of a firearm' as far as the BATFE is concerned and is counted as one of each in the 3yr totals that are required to be tabulated when renewing the license.
They don't care if it came from and went back to the same person for what ever reason. What they will want to see is either a 4473 for the disposition or the FFL copy of the dealer it was sent to should they stop by for a compliance check...and yes they check every transaction.
Not logging the gun in, trying to get the customer to decide quickly before it's logged and then if rejected, send it back w/o it being on the books doesn't work either. The dealer is still responsible for logging the entry no matter how short of a time they may have had the gun in their possession. They have til the end of the next business day to make the actual entry. I believe there is a longer period allowed for dispositions to be entered in the log as long as a business record of sales is available.