대상판결은 질권자가 제3채무자로부터 자기채권을 초과하여 금전을 지급받아 피담보채권의 변제에 충당한 다음 나머지 금원을 질권설정자에게 반환하였는데, 보상관계의 흠결이 밝혀져 제3채무자가 질권자에 대하여 지급한 금전 전부에 대하여 부당이득반환청구를 한 사안이다. 이에 대하여 대상판결은 질권자가 피담보채권의 변제에 충당한 부분에 관하여 지시관계에서의 부당이득 법리를 적용하여 제3채무자가 질권자를 상대로 부당이득반환청구를 할 수 없다는 법리를 최초로 판시하였다. 질권자가 직접청구권을 행사하여 제3채무자가 금전을 교부한 경우에 지시관계의 핵심 특징인 동시이행효, 재산의 경유적 이동을 인정할 수 있으므로 지시관계에서의 부당이득 법리를 적용한 대상판결은 타당하다. 그런데 대상판결은 초과부분에 대하여 질권자가 질권설정자에게 반환하였으므로 질권자가 실질적인 이익을 취득하였다고 볼 수 없어 부당이득반환의무를 부담하지 않는다고 판시하였다. 그러나 실질적인 이익이 의미하는 바가 무엇인지 명확하지 않고, 예금계약의 법리를 고려할 때 실질적인 이익을 부당이득반환의무 유무의 판단기준으로 삼는 것은 타당하지 않다. 대상판결의 사실관계에 비추어 초과부분에 대해서도 질권설정자의 지시가 있다고 볼 수 있고, 설령 그렇지 않다고 하더라도 질권설정자가 초과부분의 반환을 수령함으로써 지시를 추인하였다고 볼 수 있다. 따라서 초과부분에 대해서도 지시관계에서의 부당이득 법리에 따라 질권자는 제3채무자에 대하여 부당이득반환의무를 부담하지 않는다고 법리를 전개하는 것이 타당하다.
This paper studies the relations among the contracting parties and the third party in unjustified enrichment cases, focusing on Supreme Court 2012Da92258, May 29, 2015(hereinafter “the Case”). In the Case, the pledgee had received money from the third debtor, which exceeds the amount of money the debtor/pledger owed to him. The pledgee reversed the excess to the debtor/pledger. Later the contractual relations between the debtor/pledger and the third debtor was found to be void. The third debtor claimed that the pledgee should bear the obligation to reverse all of the money paid by the third debtor. The main issue of the Case is whether the pledgee bears the obligation to reverse the enrichment to the third debtor. The Supreme Court held that the pledgee does not bear such obligation, applying the doctrine of unjust enrichment previously employed in cases where a debtor directs (“anweisen” in German) the third debtor to perform his obligation to the creditor. The conclusion the Supreme Court reached in the subject case seems reasonable, as the reasoning behind the “anweisung” cases can be applied to the Case. In both cases, the third party`s performance discharges both the debtor and the third party from their liabilities; and the money or asset can be theoretically deemed as transferred from the third party to the debtor, and from the debtor to the creditor. As such, the grounds for not accepting unjust enrichment claim in “anweisung” cases can be applied to the Case. The Supreme Court also held that the pledgee in the Case had not obtained “profit in a practical sense,” because the pledgee had reversed the excess to the debtor/pledger. In other words, the Supreme Court applied the doctrine of “profit in a practical sense” here. In my view, however, expanding the scope of the doctrine to the Case seems questionable. The meaning of “profit in a practical sense” remains unclear, and such doctrine cannot provide proper standard in deciding whether the enriched person bears the obligation to reverse the enrichment. The relevant facts of the Case can be understood as follows: the third debtor was directed to pay the money (including the excess) to the pledgee by the pledger, or the debtor/pledger gave expost facto approval to the third debtor`s act by receiving the excess. As such, the doctrine of unjust enrichment in “anweisung” cases can be applied to the excess paid to the pledgee, which draws the conclusion denying the pledgee`s obligation to reverse the enrichment.