I have to say the negative trust bothers me, I don't support it, and I think it should be removed. But that is based on my personal opinion that ion.cash is sincere and is not scamming.
Because you don't believe smoothie was scammed by ion.cash and you don't strongly believe ion.cash is a scammer (as per the very definition of the negative trust) you can place positive trust on him to negate negative rating.
It's entirely legitimate to give someone a new positive rating just to negate a negative rating.
This is a first, I agree with Illodin.
I gave ion.cash a positive rating as i don't think a flame war is a trust issue--it's a clash of egos. If it was a personality rating, I'd think smoothie would have a legitimate argument for handing out negative scores based on personalities clashing.