## Facts

- Rana Samara consulted Dr. Haitham Matar, a dentist, for a missing tooth; Matar recommended an implant and referred her to oral surgeon Dr. Stephen Nahigian.
- After surgery, Samara alleged injury and sued both Matar and Nahigian for professional negligence, alleging direct negligence and that Matar was vicariously liable for Nahigian’s negligence.
- The trial court granted summary judgment for Nahigian on two independent grounds: (1) the statute of limitations barred the claim, and (2) there was no triable issue of causation.
- Samara appealed and challenged both grounds; the Court of Appeal affirmed the judgment for Nahigian solely on statute-of-limitations grounds and did not address causation.
- Matar then sought summary judgment, arguing issue preclusion barred Samara from relitigating causation based on the trial court’s earlier “no causation” determination as to Nahigian.
- The trial court granted summary judgment for Matar on that preclusion theory; the Court of Appeal reversed, and the California Supreme Court granted review.

## Issues

1. When a trial court enters judgment on multiple independent grounds and the appellate court affirms on only one ground, may an unreviewed alternative ground be given issue-preclusive effect in later litigation?
2. Specifically, can a trial court’s unreviewed “no causation” finding be used to preclude a plaintiff from litigating causation against a different defendant on a vicarious-liability theory?

## Decision

- The California Supreme Court affirmed the Court of Appeal’s reversal of summary judgment for Matar.
- The Court held that the preclusive effect of the prior judgment must be evaluated as if the trial court had not relied on the ground that was challenged on appeal but not addressed by the appellate court.
- The Court overruled People v. Skidmore (1865) to the extent it treated an appellate affirmance as conclusively establishing all trial-court determinations, including those not reviewed.
- Because the Court of Appeal affirmed Nahigian’s judgment only on limitations, the unreviewed causation determination could not support issue preclusion against Samara in her case against Matar.

## Legal Principles

- Issue preclusion requires, among other elements, that the issue was necessarily decided and that applying preclusion is consistent with fairness and public policy.
- When a judgment rests on multiple independent grounds and the appellate court affirms on one ground without addressing another ground that was challenged on appeal, the unaddressed ground is treated as having no preclusive effect.
- For preclusion analysis in later litigation, the prior judgment is assessed as though the trial court did not rely on the unreviewed alternative ground.

## Conclusion

The court held that an alternative trial-court determination that was challenged on appeal but not reviewed cannot be used to preclude relitigation of that issue in later proceedings; therefore, Samara could litigate causation and vicarious liability against Matar notwithstanding the trial court’s earlier, unreviewed “no causation” ruling in favor of Nahigian.


Samara v. Matar, 5 Cal. 5th 322, 419 P.3d 924 (Cal. 2018)