Originally Posted by
155mm
Validity and proof are two different concepts. The initial ATP applicant undergoes a logbook review by the examiner prior to the checkride to see if all the requirements are met "validity". I never saw one ask for "proof" such as maintenance logs, etc. Of course it may happen, I just haven't seen it!
It used to be that when obtaining the FAA signoff to take the written, the logbook was thoroughly reviewed, and not uncommonly the FAA did make contact with owners or operators and spot checked to verify the times. When it was required, the signoff to take the written was significant because it was a sort of stamp of approval showing that the log and the time had been vetted.