I expect that's Stewart's dilemma, whether the item was delivered or not. Without the final scan, there's nothing to point to, and given that it's someone he trusts, he has the recipient's word that he never received it. This leaves only one possibility, but it's the one that's the least helpful of the bunch as there's nothing to be done about it.

And glad you've had such success with delivery confirmation. I've never lost a shipment, but a few scans have gone missing over the years. Not many, but a few.

Scott