Kernrechtsfrage
Whether the appellate decision was invalid because it was allegedly not notified to B.
Extrahierter Entscheid
The decision had been notified; even assuming a defect, B. suffered no prejudice and could not rely on it in good faith.
Extrahierte Begründung
The file showed judicial service to both siblings at the same address, and they filed timely federal appeals, proving knowledge of the decision.