All -1 feedback threads are closed, and then re-opened only for a one-time rebuttal by the offending party. This is to avoid any unnecessary comments from others, or from two members going at it back and forth forever.
The complainant gets his complaint, the defendant gets his rebuttal.
Also, even though they fall off the screen, it is a permanent record that shows up when others search for their feedback like they should be doing before they decide to deal with people they don't personally know.