Ideally, managers that accept negative trust members should receive negative trust themselves. :/
And for what charges? Trusting the not trusted?
Trust is too vague for that.
And how about managers with negative trust managing bounty?
What about them?
I think that no manager want to accept participants with negative trust. Maybe that they forgot to include it in their bounty rule.
I assume that they are just not bothered about trust ratings. Most campaigns are up to advertising only. They want more people to know about their product/service/project so they don't pay much attention to an account's reputation.