No. You've dealt with a person who isn't trusted and has had a lot of untrusted negative feedback. You can't expect some sort of perfect trust system that can prevent every type of scam. We've seen this with people that have a decent positive trust rating eventually scamming (e.g. Bogus escrow scam).
In addition, most people who are unfamiliar with it will simply see someone marked in red and automatically assume that the person is a scammer without reading the comments in their trust feedback score.
One can't blame anyone else, for the lack of knowledge regarding the trust system, but themselves.
I did not see the negative feedback. The + and - were at 0 before I posted. I admit I should have checked past threads. The admins should also delete scammer accounts.