Kernrechtsfrage
Whether the cantonal court could estimate unpaid overtime under Art. 42(2) CO despite imperfect proof of the exact number of hours.
Extrahierter Entscheid
Yes. The employee had made the overtime highly plausible, the employer had not kept required time records, and estimation of 400 hours was permissible.
Extrahierte Begründung
The employee bore the burden of proof, but the collective agreements shifted evidentiary consequences when the employer failed to keep records. The personal logs and witness evidence made overtime and partial non-compensation sufficiently probable, so the court could estimate the amount ex aequo et bono under Art. 42(2) CO.