In addition to the previous answer, I would say that even 'hard stats kept by GC' are not really hard stats. It is really easy to log caches you have never been to and as long as you keep your logs plausible, it is unlikely that anyone will ever find out since most cache owners do not check the logs in the logbook against the logs on the cache page. The whole game of geocaching is based on the trust in people not misusing the system, but ofcourse there are always people who do so. Of course, you are only fooling yourself by doing so, but it does mess up the stat pages as you can see in the case mentioned in your question.