Firstly just how far back were they checking these logbooks or was it just a case of handing over every logbook the pilot had and CASA randomly picking an entry? I know quite a few who have 3 or 4 logbooks! You'd think it would be no mean feat to pick an entry from say 13th June 1992 for example and pulling up the records for the flights.
Also I thought when operators had their yearly audits the company pilots logbooks were routinely checked for discrepancies, anomalies etc.
There was a major investigation a couple of years ago regarding a certain C&T guy which saw many pilots losing their logbooks for about a week and then having to explain each and every flight they did with said C & T guy. From all reports that was not a pleasant experience at all considering 99% of them had done nothing wrong!