Key legal question
Whether the appeal could challenge findings requiring accounting and document access despite prior cantonal review.
Extracted holding
Rulings on alleged factual errors, hearing violations, and arbitrary application of cantonal law were not open to federal review because they were not final in light of the cantonal nullity complaint procedure; only federal-law arguments were reviewable.
Extracted reasoning
The appellant had pursued a cantonal nullity complaint against precisely those grounds, so the Handelsgericht decision was not last-instance for those complaints. Because the Kassationsgericht decision was not appealed, federal review was unavailable on those points.