I would check any and all cloud drives he might use. I personally use several as backups, so if Verizon Cloud doesn't have enough space I can also have items stored in such places as DropBox, Google Drive, Microsoft OneDrive, etc. A lot of them prompt during setup to back up automatically during wifi, so there's a possibility that they might be stored there. I had the same thing happen to me recently out of the blue, no software update or anything, but thankfully the pictures I lost appeared on my OneDrive account. Hopefully this helps 🙂
