## Facts

- Judith A. Krezinski was injured in a 1963 automobile collision allegedly caused when Izetta L. Hay entered a highway from a driveway and struck Krezinski’s vehicle.
- Krezinski received medical evaluation and treatment; at the time, her condition was not understood to include a serious permanent neurological disorder.
- In 1969, while represented by counsel, Krezinski accepted $2,300 and signed a written release discharging Hay and Hay’s insurer from claims arising from the accident, including “all known and unknown” and “developed or undeveloped” personal injuries.
- After the release, Krezinski experienced grand mal epileptic seizures later attributed by medical evidence to trauma from the 1963 collision.
- Krezinski claimed the release was executed under a mutual mistake of fact because both sides were ignorant of a latent but existing epileptic condition at the time of settlement.

## Issues

1. Whether the summary-judgment record raised a genuine issue of material fact that the release was executed under mutual mistake of fact regarding a latent, pre-existing injury causally related to the accident.
2. Whether broad release language covering “known and unknown” injuries bars a mutual-mistake challenge as a matter of law.

## Decision

- The Wisconsin Supreme Court reversed the circuit court’s grant of summary judgment to the defendants.
- The court held Krezinski submitted sufficient evidentiary materials to create a triable issue on whether the release was the product of mutual mistake concerning a latent but present condition.
- The case was remanded for further proceedings to determine the validity and effect of the release.

## Legal Principles

- A personal-injury release may be voidable if both parties entered the settlement under a mutual mistake of fact about the existence or extent of an injury that was present at the time of the release but medically unknown.
- General release terms purporting to cover “unknown” or “undeveloped” injuries do not automatically defeat a properly supported claim of mutual mistake; the parties’ mistaken assumptions and intent remain factual questions.
- Summary judgment is improper where, viewing the record in the nonmoving party’s favor, reasonable inferences support a genuine dispute over material facts such as the existence of a latent condition, causation, and the parties’ shared ignorance.

## Conclusion

Because the record permitted reasonable inferences that traumatic epilepsy existed at the time of the 1969 settlement, was caused by the 1963 accident, and was unknown to both sides when the release was signed, the court held summary judgment inappropriate and required fact-finding on mutual mistake and the release’s validity.


Krezinski v. Hay, 77 Wis. 2d 569 (Wis. 1977)