Most of my flights, there's no proof that I've flown the airplane. There's no log in the aircraft with my name on it. The flight was VFR, perhaps, with no tower involved, and many times, I don't talk on the radio at all. Some aircraft don't even have an electrical system. No hobbs. No daily tracking in the airplane, no book, no can. No paperwork to fill out. If I choose to log it, great. If I chose not to log it, big deal. The FAA couldn't care less unless I violate a regulation.

The only time that the FAA has taken an interest in reviewing my logbooks was my application to take the ATP written, when an FAA endorsement was required to do so. Back then, getting the endorsement was a sort of FAA stamp of approval noting that the logbook had been vetted and reviewed, and it wasn't uncommon for an inspector to do spot checks with former employers or operators of the aircraft in the logbook, to verify that the times were true and correct. Back then, having the signoff to take the ATP written (it actually was a written test) was considered verification that the time was real. Approval to take the ATP test meant something. Today it doesn't mean a thing.

Unless you're suspected of falsifying your logbook, there's no earthly reason to pick apart your log. You're not required to back up each flight with an official source; that's a European thing. Unless you're caught in the EASA nightmare, where one is expected to get a signature in the log everywere he goes to prove he was really there (in Europe, they have stamps for each stop in general aviation), it's pointless. In the USA we don't do that. Consequently, you don't need to independently verify that you really flew those hours.

If there was a requirement to independently verify your hours, apart from your logbook, it would be codified in the regulation. Can you find any part of Part 61 which demands or even suggests that you should have alternate documentation to establish veracity for your logbook?