Facts
[B. AG] (respondent) obtained on 13 August 2018 from the Meilen District Court three attachment orders against [A.] (appellant) for two claims of CHF 994'500.-- each plus interest. Attached were balances at Stiftung [C.] (Debt Enforcement Office Zurich 11), balances at Bank [D.] (Debt Enforcement Office Oberland), and share certificate No. 1 for 25'000 registered shares deposited with a lawyer (Debt Enforcement Office Pfannenstiel).
The appellant lodged a timely objection on 8 October 2018. On 11 January 2019 he withdrew the objections. By order of 15 January 2019, the District Court closed the proceedings, imposed on the appellant the court fee of CHF 1'000.-- and ordered him to pay the respondent party compensation of CHF 19'300.--. The District Court based this on the attachment claims as the amount in dispute.
By appeal of 28 January 2019 the appellant applied to the Zurich Cantonal Court, II. Civil Chamber, for the party compensation to be fixed on the basis of a correct amount in dispute of at most CHF 8'183.15 (estimated value of the attachment assets), alternatively for remittal to the District Court. The Cantonal Court dismissed the appeal by judgment of 8 March 2019.
By civil law appeal or, in the alternative, subsidiary constitutional appeal of 12 April 2019, the appellant brought the matter before the Federal Supreme Court and requested the annulment of the cantonal judgment and the fixing of party compensation on the basis of the estimated value of CHF 8'183.15. The respondent and the Cantonal Court waived a response.
Central question: Is fixing the amount in dispute for party compensation in attachment objection proceedings on the basis of the attachment claims, rather than the value of the attachment assets, arbitrary or unconstitutional?
Considerations
The civil law appeal is admissible, given that the amount in dispute of CHF 30'000.-- (Art. 74 para. 1 lit. b FSCA) is not reached, only where a legal question of fundamental importance arises (Art. 74 para. 2 lit. a FSCA). The decision on an objection to an attachment order is treated as a provisional measure within the meaning of Art. 98 FSCA, so that only the violation of constitutional rights may be asserted (Art. 106 para. 2 FSCA). The submission is therefore treated as a subsidiary constitutional appeal (Art. 113 FSCA), since review of the legal question of fundamental importance with unrestricted cognition could not be achieved. The application of federal law is reviewed only for arbitrariness (Art. 9 Cst.).
Court fees in DEBA summary proceedings are governed by federal law (Art. 16 para. 1 DEBA in conjunction with Art. 48 et seq. FeeO-DEBA), whereas party compensation is assessed under the cantonal tariff (Art. 105 para. 2 in conjunction with Art. 96 CPC). According to the prevailing view, the determination of the amount in dispute for costs is made under federal law (Art. 91 et seq. CPC), although the question whether cantonal calculations deviating from this are permissible remains open, since the appellant does not complain of this and the amount in dispute can be reviewed only for arbitrariness.
Whether the amount in dispute should be based on the attachment claim or the estimated value of the attachment object is disputed in legal scholarship and case law and has not yet been conclusively settled by the Federal Supreme Court (BGE 139 III 201 E. 4.3.2). According to the Federal Supreme Court's practice, assessment on the basis of the value of the attachment assets and, if that value is unknown, on the basis of the attachment claim is not arbitrary (BGE 139 III 195 E. 4.3.3). For bank balances, for example, the bank need only provide information after the objection has been finally resolved (BGE 125 III 391 E. 2). If the value of the attachment assets is known, for example through an estimate by the debt enforcement office, relying on the attachment claim is not appropriate.
In the present case three debt enforcement offices were involved. Only the Debt Enforcement Office Oberland had estimated the balances at Bank…