Update: I am sure when you do a Super Search on this topic you will find one (almost) universal fact, people who post nodes complaining about losing XP get said node downvoted.
In this case, his description of what he thinks happened could arguably be a symptom of some bug within Perl Monks. With the recent changes, it certainly is worth raising the red flag just in case.
I suspect his perception of the events could be to blame, but I've had several posts that seem to start out at a negative reputation seemingly before anyone could have read the post and voted, so it wouldn't surprise me at all if there was a "feechur" lurking around the monestary.