In Hogbin v. Hogbin-DeLaurentis, the Appellate Court in NJ permitted the wife the opportunity to present proofs ( to the court below on remand) as to whether the parties settlement agreement was oppressive and manifestly unfair and should be set aside, based on her testimony as to her husband's physical & emotional abuse and the report of her expert as to her mental state at the time the agreement was entered.
Translated to english....... where one side clearly pressures the other side into accepting an unfair settlement agreement or where one side is clearly in an emotionally unstable state of mind, the agreement may ultimately be thrown out by the court.