The airplane could have easily been damaged in a wind storm, or even damaged in a flight accident that did not require reporting to the Feds.
In any case, the repairs are at least documented, I'm surprised the present owner is ignorant of the log entrys, or so stupid to believe that a prospective buyer would not stumble upon the entries and question the NDH claim.
We've discussed damage history (and the affect if might have on value) at great lengths and if you do some searches using different key words, you will find the threads on this subject.
It is fairly common to find undocumented repairs to an airplane, however, I'm sure most repairs are properly documented, as are the ones you are looking at. As far as the disagreement between NTSB reports and the logs, as I noted, not all accidents and incidents need be reported to the FAA or the NTSB, as I hope you learned while studying for the private pilot exam.
Needless to say, some of the reportable ones are not reported.
Charles.
