Key legal question
Whether the cantonal court arbitrarily applied German law by treating the notarial debt acknowledgment as abstract under § 781 BGB.
Extracted holding
No. The wording, purpose, and enforcement submission supported an abstract acknowledgment; the debtor did not prove a merely causal acknowledgment.
Extracted reasoning
The court relied on the text of the deed and German doctrine; the burden of proving a causal acknowledgment lay on the debtor, and that proof failed.