## Facts

- In 1969, Raymonde Aleta Slater, a minor, was injured while riding as a nonowner guest passenger in a car driven by John Robert Blackwood and owned by Escondido Tire Supply Co., Inc.
- In March 1970, Slater sued for personal injuries under California’s automobile guest statute (Veh. Code § 17158), which limited a guest’s recovery to injuries caused by the driver’s intoxication or willful misconduct.
- In the first action, after plaintiff’s opening statement, the trial court granted a nonsuit and entered judgment for defendants under Code Civ. Proc. § 581c because plaintiff’s anticipated proof did not show intoxication or willful misconduct.
- Slater appealed, contending § 17158 was unconstitutional and that ordinary negligence should suffice; the Court of Appeal affirmed, and the California Supreme Court denied review in June 1972, making the judgment final.
- In February 1973, the California Supreme Court decided *Brown v. Merlo*, holding the guest statute unconstitutional as applied to injured nonowner guests.
- In May 1973, Slater filed a second lawsuit against the same defendants arising from the same 1969 accident, alleging ordinary negligence and seeking application of *Brown* to her claim.
- Defendants demurred on res judicata grounds; the trial court sustained the demurrer without leave to amend and dismissed the second action.

## Issues

1. Whether *Brown v. Merlo*’s constitutional invalidation of the guest statute should apply retroactively to permit a second civil action after a final judgment under the statute in an earlier action.
2. Whether the second complaint alleged a different “cause of action” (negligence) such that res judicata did not apply.
3. Whether a court may decline to apply res judicata on general “fairness” grounds in this setting.
4. Whether defendants were equitably estopped from asserting res judicata because plaintiff allegedly was prevented from fully litigating the statute’s constitutionality in the first action.

## Decision

- The California Supreme Court affirmed the dismissal of the second action.
- *Brown v. Merlo* was not applied to reopen or avoid civil judgments that were already final before *Brown* was decided.
- The first action’s final judgment was res judicata and barred the second suit because both actions arose from the same injury-producing event and implicated the same primary right.
- The court rejected a broad discretionary “fairness” exception that would allow relitigation whenever later law changes.
- The court rejected estoppel because plaintiff had, in fact, raised and litigated the constitutional challenge in the first action through the appellate process.

## Legal Principles

- A final judgment on the merits between the same parties is conclusive as to the same cause of action, even if the judgment rested on a legal rule later overruled or a statute later held unconstitutional.
- A change in constitutional law generally does not retroactively disturb final civil judgments; cases still pending on direct review may be treated differently from cases already final.
- Under California’s primary-right theory, a cause of action is defined by the plaintiff’s harm and the defendant’s violation of a single primary right; new legal theories (e.g., negligence vs. willful misconduct) based on the same injury do not create a new cause of action for res judicata purposes.
- Courts do not possess a general equitable power to disregard res judicata in ordinary civil litigation solely because later developments make the earlier result seem unfair.
- Equitable estoppel requires a basis showing the opposing party prevented full litigation; where the constitutional issue was raised and adjudicated, estoppel does not defeat res judicata.

## Conclusion

The court held that the final judgment in Slater’s first guest-statute action barred her later negligence action based on the same accident, and that the subsequent constitutional decision invalidating the guest statute did not retroactively unsettle final civil judgments.


Slater v. Blackwood, 15 Cal. 3d 791 (Cal. 1975)