Yes, this is what I assumed had happened and was commenting on. Maybe I just pay too much attention to karma because I'm green as grass, but I don't think I've ever cast a vote without thinking through what I find valuable about the post and how that compares to its current total. The fact that apparently a lot of people cast what I would call impulse votes is making me reevaluate exactly what it is that 'karma' is measuring.
Edit: Oh, I just realized - the anti-kibitzer hides karma scores as well as usernames. Probably there's a large subset of voters who don't and can't take relative totals into account until someone comments on it.
Of course, if someone considers that a good reason to reverse their vote I don't know why they would be using the anti-kibitzer in the first place.
I still don't think anyone here should feel good about paying attention to current total while deciding whether to upvote or downvote. Share evidence, not conclusions. The net karma a comment ends up at should be the result of aggregating our valuations, not a result of, say, whether those who thought it should be at +100 voted before or after those who thought it should be at +2.
Edit: it's clear to me now that I don't have a good solution to my perceived problem.
From this 2001 article:
I, at least, found this amusing.