Question juridique clé
Whether X. could still invoke good-faith possession and keep the collected rents after the ownership judgment became final.
Solution extraite
X. could not rely on good faith because, in the circumstances, he failed to exercise the attention required by Art. 3(2) ZGB and should have clarified his legal position.
Motifs extraits
The court held that no general duty exists to investigate, but where there are concrete reasons for doubt a party must seek clarification. The lower courts permissibly found such reasons here, given the prior litigation, the ownership judgment, the parties' strained relations, and the surrounding circumstances. The appellant's personal health complaints could not be reviewed as they depended on evidence assessment.