A counter rating (to counter false 'risked BTC' figures by people who were not party to the transaction) should only have been left if Vod believed OgNasty to be a scammer (or if OgNasty were to lose control of his account), which doesn't seem to be the case here. A more appropriate measure would be distrusting people whose ratings Vod doesn't trust. That's how the Trust system is supposed to work, negative ratings for scammers, and a removal from one's own Trust list of people who have poor character judgement, or who leave inaccurate ratings.