Facts
Parties and subject matter of proceedings: The appellant (defendant) was, together with respondent 1 (plaintiff 1) and the later deceased plaintiff 2, a partner in a simple partnership 'Konsortium [F.] ' under the partnership agreement of 29 June 1993. The subject matter is a contract supplementation concerning the general contractor fee (GU fee) and the binding effect of remittal decisions. The judgment and order of the Obergericht of the Canton of Zurich, First Civil Chamber, of 7 December 2018 are challenged.
Contractual basis: The defendant's stock corporation was to carry out the development as general contractor with open accounting and a GU fee of 4 per cent (no. 4.1.2). The consortium accounting was likewise entrusted to the stock corporation (no. 6.1). The consortium was to be dissolved after the overall accounting (no. 7.1).
Altered project sequence: The purchase option was cancelled; the Canton of Zurich acquired the plot directly and commissioned the defendant's stock corporation with the development at a price of CHF 20 million (lump-sum price, warranty for planning services). The plaintiffs demanded their share of profits after deduction of the GU fee; the defendant disputed the continued existence of the partnership and the consortium-based realisation.
Procedural history: The action was filed on 8 February 1999 with the Bezirksgericht Meilen and, after transfer, was conducted before the Bezirksgericht Zurich. The action against the stock corporation was withdrawn. The Bezirksgericht dismissed the action in 2004; the Obergericht remitted the proceedings in 2008; a partial judgment of 2010 obliged the parties to account. The Obergericht dismissed the accounting claim in 2011; the Federal Supreme Court set this aside with the 1st remittal decision (4A_619/2011, 20 March 2012). On 13 November 2014 the Bezirksgericht partially awarded the plaintiffs shares of profit. On 11 November 2015 the Obergericht confirmed this and rejected a surcharge to 9 per cent instead of 4 per cent, primarily on the ground that 4 per cent was binding under the 1st remittal decision, alternatively on the ground of a lack of increased assumption of risk. With the 2nd remittal decision (4A_696/2015, 25 July 2016) the Federal Supreme Court rejected the binding effect of the 4 per cent, affirmed a contractual gap due to increased risk (lump-sum price and planning warranty), and remitted the matter for determination of a surcharge, if necessary with an expert opinion, and for a reduction on account of the possibility of asserting costs against the partners. In addition, the interest calculation was corrected.
Expert opinion and judgment of the lower court: The Obergericht obtained an expert opinion from [E.] (expert, respondent 3). The expert rejected an additional surcharge, since the fee-bearing construction sum was to be increased by the planners' fees, the cost risk was negligible, and a cost estimate with 10 per cent inaccuracy had been lower than the lump-sum price. He took into account a standardised project (three similar developments, inspection on site) and interviews. On 7 December 2018 the Obergericht ordered the defendant to pay plaintiff 1 CHF 316,740.93 and plaintiff 2 CHF 329,116.90 plus interest, and compensated the expert with CHF 32,158.20.
Applications and proceedings before the Federal Supreme Court: The defendant applied for annulment of the judgment, dismissal of the claim and waiver of the expert's fee, alternatively its reduction. The plaintiffs applied for dismissal of the appeal. A genuine new submission concerning waiver declarations of limitation and the death of plaintiff 2 (23 May 2019) was filed. The proceedings were stayed until the succession had been clarified. The executor (respondent 2) was entered in the caption in place of the deceased. The expert was listed as respondent 3, since the appellant seeks a reduction of his fee.
Considerations
Standing and novel submissions: The executor is a party to proceedings concerning the assets and liabilities of the estate, insofar as administration rests with him (Art. 518 CC). An expert may have standing to appeal if his fee has been reduced. Genuine novel submissions are in principle inadmissible (Art. 99 para. 1 FSCA). The waiver declarations of limitation were not admitted, since no plea of limitation had been raised and claims for restitution are not the subject matter of the proceedings. Payment under a reservation of restitution is a genuine novum without significance for the requirements for a substantive judgment; the objection would have to be raised in enforcement proceedings.
Binding effect of the remittal decision: Courts and parties are bound by the legal assessment of the remittal decision; the new assessment is limited to the framework and the elements for whose clarification the matter was remitted (BGE 143 IV 214; 135 III 334; 131 III 91). The Federal Supreme Court examines the facts only for arbitrariness (Art. 105 para. 2 FSCA) under the strict principle of complaints (Art. 106 para. 2 FSCA). The lower court did not violate the 2nd remittal decision: the Federal Supreme Court proceeded on the basis that fair parties would be guided by the customary remuneration of additional services; the increase of the fee-bearing construction sum by the planners' fees already constituted compensation for the additional services. A further surcharge was therefore not necessarily required under the meaning of the remittal decision; the wording is explained by the fact that the lower court had at that time not assumed any change in the performance. The construction sum had not been challenged in the remittal decision and was rightly not reduced. A possible overcompensation as a result of the plaintiffs' poor conduct of the proceedings was not examined for lack of a sufficiently substantiated argument.
Delegation to the expert and assessment of evidence: The contract supplementation is a question of law (hypothetical will of the parties according to good faith, CC concept, orientation to the conduct of reasonable and fair contractual partners), which the Federal Supreme Court reviews freely but with restraint; factual findings on the hypothetical will are binding. The lower court did not carry out a contract supplementation and did not delegate the legal question. An expert opinion is subject to free evaluation of evidence, which is reviewed only for arbitrariness (BGE 138 III 193). The court may depart from the expert…