Many personal injury cases that appear on court calendars, as well as many not filed, are settled before trial. Settlements usually involve payment by the alleged wrongdoer in consideration of a release executed by the injured party. As for the alleged wrongdoer, this act settles the conflict in that the releasor has bargained away his legal remedy. As for the releasor, compensation for the injury was his objective. Sparse authority to the contrary, a release constitutes a contract, the validity of which can be affected by fraud, duress or mistake. Generally, one need not go into equity and pray for specific relief from the release on one or more of these grounds. The majority of jurisdictions permit the injured party to bring his action, notwithstanding the previous release of all claims. By way of replication to the defense of release, the injured party sets up his contention for avoidance. It is thereby possible, under this procedure, to avoid the release and bring the suit in one action at law.
Paul D. Malina, Unilateral Mistake of Fact in Personal Injury Releases, 10 Clev.-Marshall L. Rev. 70 (1961)