The same thing happened to me, this user nutildah https://bitcointalk.org/index.php?action=profile;u=317618  
wrongly accused me of something, i confronted him and he continue with the same sociopath pathological behavior towards me, as i was new and did not understand well this trust system i follow his steps and wait for him to support a scam, and when i found out that he was supporting VIVA-e scam i put a negative trust on nutildah profile, because if the rule apply to me because i was apparently supporting the scam exchange tradesatoshi then nutildah deserve the negative review i left on his profile, we are all the same under the forum rules. Misteriusly later the post where he was supporting the scam got deleted, but i was able to archive it with a nice tool i found on google.

So my advice is, wait for that person to support a scam and then flag him as supporter of the scam as i did with the scammer nutildah