I didn't read all the comments completly but a simple solution could be. Both parties have 30 days to leave feedback and it is not visable to anyone untill both parties have left feedback or 30 days is up.After the thirty days if only one party has left feedback then only their feedback is shown and the other party is out of luck and also can not retaliate or post any reason or note.However the person who did leave feedback within the time frame (could also be both parties) is allowed one follow up note to describe the situation.