Key legal question
Whether the defendant's set-off based on an assigned claim was an abusive exercise of rights
Extracted holding
No abuse was shown; acquiring a claim to create a set-off position is not, by itself, manifestly abusive.
Extracted reasoning
The assignment transferred the claim with all advantages and disadvantages; the plaintiff could raise all defenses against the assignee under Art. 169 OR, but did not do so. No special circumstances justified treating the set-off as abusive under Art. 2(2) ZGB.