Questão jurídica principal
Whether the cantonal court committed excessive formalism by refusing to treat the first-instance filing as a counterclaim
Decisão extraída
No excessive formalism: the appellant had raised only a set-off defense in first instance, and the counterclaim was raised for the first time on appeal.
Fundamentação extraída
The court held that set-off and counterclaim are distinct. The complaint was also inadmissible because the new grievance had not been raised before the cantonal appeal court and the appellant's conduct was contrary to good faith.