Kernrechtsfrage
Whether Art. 271a(1)(e) OR makes a landlord's termination voidable within three years after a prior proceeding even if the first case only concerned a formal defect.
Extrahierter Entscheid
No. The three-year retaliation bar applies only if the earlier dispute also concerned substantive tenancy issues; a proceeding limited to a formal nullity finding is insufficient.
Extrahierte Begründung
Art. 271a complements Art. 271 OR and presumes abusiveness in typical retaliation situations, but the statutory protection does not bar a renewed notice merely because an earlier notice was invalid for form reasons. The prior proceeding must have related to substantive rental-law matters; otherwise the second notice is not covered by the retaliation rule.