Happened 2 times so far in 10 days on my bounties Sapien and Xwin the sad part is we can do nothing about it, negative trust I think it doesn't maters. They probably never log the forum after payments.
They wont really care at all even if their accounts being tagged with negative since their job is done on accumulating millions of money to its investors and forum account isnt really an issue for them but this would really give negative impressions to the project itself.It might be on minimal effects but once the entire community will know on the behavior that they have done this would still end on failure.