Generally speaking, New Jersey statutes and court rules cloak settlement negotiations with secrecy (legally, called a “privilege”) such that what goes on in those proceedings are not evidential, that is, they are “privileged” from being disclosed to a court.
Somewhat of an exception arises in cases in which the negotiations produce an oral agreement. Let’s first deal with this in the context of settlement negotiations not in the mediation context. Usually, it happens this way: the parties are participating in a “4-way” settlement session in which each party is present (either physically or by phone), as is their attorneys. Through the negotiations, agreement is reached as to the basic provisions such that both parties walk away from the session thinking that they have reached a binding agreement, albeit oral, subject only to “finalizing” it by reducing it to writing (and filling in details that would normally expand the basic terms during the drafting process), approved by the attorneys, and signed by the parties. One of the parties then changes his or her mind before any written agreement is signed. The other party says “wait a minute, you can’t do that, we had an oral agreement. You can’t change your mind.” The party backing off of the arrangement says “but we did not have a full agreement. There were many terms and details still to be negotiated.”