The moderation tools show the lowest voted answers, but is it sensible to show answers with just -1 votes? I'd venture to suggest that it isn't generally helpful. As of a couple of minutes ago (2010-01-01 20:37 -08:00), there was one answer with -1 vote listed. I suspect there were more such answers, but only space for one in the list. I'd venture to suggest that one downvote doesn't not usually warrant the listing.
There's also a time component to that list (2 days being the default) so I'm pretty confident that the question listed with -1 votes is probably the most recent question with that score. All of the lists on the moderation page look to be set up to display 15 links. If there aren't enough answers voted lower than -1 to fill the list, it makes sense to me that it should be filled out with the most recent questions from selected time period with -1 votes.