Key legal question
Whether the cantonal court had to join co-liable former director A. as a third party in the damages proceedings.
Extracted holding
Yes. A. was a potentially co-liable solidary debtor already pursued by the compensation office and therefore had to be joined so the court could hear him before deciding.
Extracted reasoning
The purpose of joinder is to extend the judgment's res judicata effect to affected third parties and to respect the right to be heard. Existing case law requires joinder of other solidary debtors targeted by the compensation office, even if their liability is already final. Because A.'s position and possible further instalment payments could still affect the allocation of damages among the remaining directors, a remand was necessary.