"The person is a scammer or i think he will scam"
^ thats the reason when you give neg-trust...
that doesnt sound like a warning to me.
i've added a comment on quicksellers account...THAT is a warning... neg-trust is saying "he will scam"
"He will scam".

I don't think your feedback says that:
onemorexmr 0: -0 / +0(0) - 2015-03-1 - abuses trust system. please check references from people who get neg-rated by him very carefully and decide for yourself.
i think he abuses the trust system, because quickseller states in his neg-trust that op is impersonating another one AND will scam (the second part is implicit by selecting the neg-trust instead of comment)