## Facts

- A father was subject to a conservatorship.
- The probate court entered a substituted-judgment order under California Probate Code § 2580 et seq., authorizing execution of a living trust and pour-over will as the conservatee’s estate plan.
- The authorized estate plan effectively disinherited the conservatee’s son.
- After the father’s death, the son sued his sister, individually and as trustee, asserting claims including breach of oral contract, undue influence, intentional interference with contract, and fraud.
- The son obtained a post-death judgment imposing a constructive trust over one-half of the decedent’s property.
- The sister appealed, arguing the son’s action was barred by collateral estoppel based on the earlier substituted-judgment proceeding.

## Issues

1. Whether a probate court’s substituted-judgment order approving an estate plan has issue-preclusive effect in later civil litigation by a disinherited heir challenging the plan.
2. Whether the issues advanced through post-death tort and contract theories were actually litigated or necessarily decided, or could have been litigated, in the substituted-judgment proceeding.
3. Whether applying collateral estoppel serves the finality and administration purposes of the substituted-judgment statutory scheme.

## Decision

- The Court of Appeal reversed the judgment in favor of the son.
- The court held, as a matter of first impression, that principles of collateral estoppel barred the son’s civil action.
- The substituted-judgment order was treated as a final adjudication approving the legitimacy of the estate plan within the conservatorship process.
- The court concluded the son could not relitigate, through later tort and contract claims, issues resolved (or necessarily resolved) when the probate court authorized the estate plan.
- The court emphasized that allowing post-death collateral attacks would undermine the purposes of substituted-judgment proceedings and the finality of probate court orders.

## Legal Principles

- Collateral estoppel bars relitigation of issues actually litigated or necessarily decided in a prior proceeding where the party to be bound had a full and fair opportunity to contest those issues.
- A substituted-judgment proceeding under Probate Code § 2580 et seq. authorizes a probate court, within the statutory limits, to approve execution of testamentary instruments on behalf of a conservatee when a reasonably prudent person in the conservatee’s position would do so.
- A final substituted-judgment order approving an estate plan can preclude subsequent civil claims that function as an attack on the validity or propriety of the court-approved plan.
- Policy considerations supporting preclusion include protecting the integrity and finality of probate court determinations made within conservatorship administration.

## Conclusion

The court held that the probate court’s substituted-judgment order approving the conservatee’s trust-and-will estate plan precluded the disinherited son’s later post-death tort and contract action against the trustee, and it reversed the judgment granting the son relief.


Murphy v. Murphy, 164 Cal. App. 4th 376 (Cal. Ct. App. 2008)