@full-steem-ahead I couldn't reply because of nesting depth, but hopefully you will see this:

Also, doesn't down-voting negatively affect a user's rep score?

Only when the downvote pushes the post value negative (which will show, and pay, as zero), and even then only when the person making the downvote has a higher rep score than the author (not the case here). When downvoting to reduce a payout (but the payout remains above zero), assuming your rep score is higher than the author's, the effect is to reduce the degree that rep is increased by the post, but not to actually decrease it.