I launched this thread with an example but it was still launched with the question "how do you prevent potential abuse from a Default Trusted member", from here I will leave matter experts to decide if that is a valid question or not and what is the answer to it.
The main thing to do is to determine whether it's a case of abuse or just a misunderstanding or being too harsh, and try to be reasonable instead of leave fake retaliation feedback and attack the user who left the trust you disagree with.
You failed completely on this.
Some steps I'd recommend to handle DT abuse:
- First, read the left feedback and the reference (if any) and try to understand the reason.
- If you don't understand it or find it unfair then PM that user to ask for more information and explain your side of the story.
- Avoid reaching wrong conclusions like the one you reached. "It must be to kill competition because I can't find any other reason considering it's impossible I'm wrong. " is usually wrong.
- Avoid leaving fake retaliation feedback. You can leave negative feedback if you know for a fact it's abuse after gathering some proof. (I see you haven't fixed this error of yours until now)
- If it's not possible to solve it via PM and you still disagree with the trust then create a thread on Reputation explaining everything, without attacking anyone. If most users agree with you then almost certainly the DT user will remove the negative trust. If the community reaches the conclusion it's really abuse (or unfairly harsh) then you can be sure the DT user will be removed from DT by other DT1 users.