Facts
A. - By a publicly certified marriage contract dated May 26, 1982, Hans and Anita [G.] chose the general separation of property regime instead of the previous ordinary community of property. Among other things, they agreed that claims against [Z. AG] and other legal entities totaling CHF 545,000 should be transferred to the wife.
B. - On September 16, 1985, Hans and Anita [G.] concluded an agreement with [Z. AG] and other parties to settle the disputes between them. Among other things, [Z. AG] undertook to make a payment of CHF 150,000 to the debt collection office in Chur for Hans [G.] to satisfy his known debt collection creditors at the time. Furthermore, [Z. AG] transferred to Hans [G.] the property at X-Strasse in C. at an accounting value of CHF 2,350,000, against the assumption of the existing mortgages amounting to CHF 1,900,000. In a supplement dated October 17, 1985, the same parties agreed that the said property should be transferred to Anita [G.] instead of Hans G.
C. - With a claim filed on May 11, 1988 against Anita [G.], T. challenged this transaction based on Art. 288 of the Debt Enforcement and Bankruptcy Act (SchKG) before the District Court of Plessur. The District Court dismissed the claim on August 30, 1988, which the Cantonal Court of Graubünden confirmed on February 7, 1989.
Considerations
2. The Cantonal Court dismissed the claim primarily because no final certificate of loss was available. The plaintiff sees this as a violation of federal law, as the law allows a provisional certificate of loss to be sufficient and it is not possible for him to submit a final certificate of loss, as there is a pending objection procedure between him and the defendant regarding the objects seized in the corresponding debt collection.
a) According to the previous case law of the Federal Court, the existence of a certificate of loss is a prerequisite for active legitimacy. With a provisional certificate of loss, the active legitimacy is subject to a resolutive condition. If no final certificate of loss is submitted by the time of the judgment, it lapses. The reasoning is that the provisional certificate of loss does not conclusively prove the creditor's loss.
b) Exceptionally, the Federal Court allows a provisional certificate of loss to be sufficient if the challenge action is intended to eliminate a third-party claim that was raised in the debt collection that led to this provisional certificate of loss. In this…