dissenting. In reversing the Appellate Court the majority relies primarily on the “important public policy prohibiting double recovery,” but completely overlooks the important public policy of preventing unmerited windfalls at the expense of others. See Gorham v. Farmington Motor Inn, Inc., 159 Conn. 576, 580, 271 A.2d 94 (1970). As the opinion recognizes, General Statutes § 38-174n provides for a lien by a medical insurer that has furnished benefits to an insured who has suffered an injury covered by the Workers’ Compensation Act upon any award to such an employee. It also requires the workers’ compensation carrier to reimburse the medical insurer to the extent of such lien, “provided such plan, policy or contract provides for reduction, exclusion, or coordination of benefits of the policy or plan on account of workers’ compensation benefits.”1 Although the record does not indicate that any such lien has been filed by the medical insurer that has paid the plaintiff’s bills of $175,521.43, the statute does not specify when such a lien must be filed. Apart from § 38-174n, an insurer that has paid the medical expenses of an injured employee pursuant to its insurance contract may well be entitled *464to indemnity against the primary obligor, the workers’ compensation carrier. Restatement, Restitution § 76.2
Because the insurer that has paid the plaintiff’s medical expenses has an interest in this litigation “of such a nature that a final decree cannot be made without either affecting that interest, or leaving the controversy in such condition that its final termination may be wholly inconsistent with equity and good conscience”; Shields v. Barrow, 58 U.S. (17 How.) 130, 139, 15 L. Ed. 158 (1855); we should remand the case to the trial court for joinder of that insurer as a necessary party.3 “The necessary party rules originated in equity and expressed the principle that a court of equity, once it undertook a case, would not do justice ‘by halves but would seek to clean up the whole controversy.’ ” F. James & G. Hazard, Civil Procedure § 10.11. In proceeding to adjudicate the plaintiff’s claim for medical expenses without notice to the insurer that paid them, in disregard of its right to reimbursement, we violate these principles by leaving the controversy in such a condition that either another suit to determine the *465medical insurer’s claim must be brought or the defendant workers’ compensation carrier will receive an undeserved windfall.
It is inconceivable that a court should attempt to decide a dispute between two thieves over property in the possession of one of them belonging to an owner whose identity is known or ascertainable without notifying him and providing an opportunity for assertion of his rights. That grotesquerie is not so far removed from the present case, in which the workers’ compensation commissioner, without notice to the medical insurer, undertook to resolve claims to the sum representing the medical expenses by one party, who seeks to recover expenses he has never incurred, and by another, which asserts entitlement to a windfall resulting from the failure of the medical insurer thus far to file a statutory lien or otherwise pursue its right of reimbursement. This court ought not to be restricted to such distasteful choices when the alternative of requiring joinder of the medical insurer is available for a complete resolution of the controversy.
Accordingly, I dissent.
The record does not indicate whether the plaintiffs medical insurance policy contained a provision relating to workers’ compensation.
The Restatement of Restitution § 76 provides: “A person who, in whole or in part, has discharged a duty which is owed by him but which as between himself and another should have been discharged by the other, is entitled to indemnity from the other, unless the payor is barred by the wrongful nature of his conduct.”
The quotation from Shields v. Barrow, 58 U.S. (17 How.) 130, 139, 15 L. Ed. 158 (1855), refers to “indispensable parties,” not merely “necessary parties.” The latter are defined as “[p]ersons having an interest in the controversy, and who ought to be made parties, in order that the court may act on that rule which requires it to decide on, and finally determine the entire controversy, and do complete justice, by adjusting all the rights involved in it.” Id. Despite the overlap in the two definitions, the medical insurer is more properly characterized as a necessary rather than an indispensable party at this point of the proceeding in this case because its rights are not affected by the determination reached by the majority, which rejects the claim of the employee. If the employee had prevailed, the medical insurer might well have been an indispensable party since the fund to which its lien relates might have disappeared.