Samara v. Matar, 234 Cal. Rptr. 3d 446

Samara sued two dentists (Nahigian and Matar) for professional negligence, alleging Matar was vicariously liable for Nahigian’s conduct.
Trial court entered summary judgment for Nahigian on two independent grounds: statute of limitations (timeliness) and lack of causation.
On appeal, Samara conceded timeliness but asked the Court of Appeal to reverse the no-causation ruling; the Court of Appeal affirmed on the timeliness ground and expressly declined to reach the causation issue.
After remittitur, Matar moved for summary judgment asserting the trial court’s unreviewed no-causation ruling precluded Samara’s claim against him; the trial court granted summary judgment for Matar on that basis.
The Court of Appeal reversed, holding preclusion did not apply; the Supreme Court granted review to address the continuing viability of People v. Skidmore.
The Supreme Court overruled Skidmore and held that an unreviewed trial-court ground (one relied on below but not embraced by the appellate court) should not be treated as having preclusive effect in later litigation.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Whether Skidmore remains good law and whether an unreviewed trial-court ground can have preclusive effect	Skamara: appellate omission of an alternative ground means it should not bind future litigation; unreviewed grounds lack finality	Matar: Skidmore permits treating a trial-court determination as preclusive even if appellate affirmance rests on another ground; trial-court judgments are presumptively correct	The Court overruled People v. Skidmore and held that a trial-court determination relied on below but not addressed by the appellate court should not have preclusive effect in later cases
Whether claim or issue preclusion barred Samara’s claim against Matar given the earlier judgment for Nahigian	Samara: preclusion inapplicable because the causation ruling was not reviewed and the affirmed judgment rested on timeliness, not merits	Matar: prior judgment should preclude relitigation of causation and bar vicarious liability	The Court held neither claim nor issue preclusion applied; the causation issue was not necessarily decided for preclusion and the timeliness affirmance did not constitute a final judgment on the merits for claim preclusion

People v. Skidmore, 27 Cal. 287 (Cal. 1865) (historical authority treating an affirmed judgment as preclusive regardless of the appellate ground)
Mycogen Corp. v. Monsanto Co., 28 Cal.4th 888 (Cal. 2002) (distinguishing claim and issue preclusion and describing primary-right theory)
DKN Holdings v. Faerber, 61 Cal.4th 813 (Cal. 2015) (explaining the elements of issue and claim preclusion)
Lucido v. Superior Court, 51 Cal.3d 335 (Cal. 1990) (discussion of preclusion terminology and scope)
Vandenberg v. Superior Court, 21 Cal.4th 815 (Cal. 1999) (considerations on preclusion and reviewability, including limits for arbitration)
Denham v. Superior Court, 2 Cal.3d 557 (Cal. 1970) (presumption of correctness of trial-court judgments on appeal)
Agarwal v. Johnson, 25 Cal.3d 932 (Cal. 1979) (appellate process and finality; unsatisfied trial judgments lack preclusive effect)