Memorandum of (mis)understandingurther, the Court found that the MOU removed a binding RfSA date from the contractual framework, and with it any entitlement to liquidated damages. The Contract contained an absolute obligation to achieve Sail Away by a certain date, whereas the MOU replaced that with an obligation to use “fullest endeavours” to achieve a different stage (Mechanical Completion) which was not absolute. The MOU did not make any mention of sanctions for failing to do so, nor (as pointed out, oddly, by Aker) did it “even refer to RfSA or liquidated damages”. The MOU obligation to use “fullest endeavours” was contradictory to the Contract obligation to achieve RfSA by a fixed date, and so obviously superseded it. In those circumstances, provided HSM utilised their “fullest endeavours”, they would not be in breach of contract, let alone liable for liquidated damages, regardless of when Mechanical Completion or RfSA actually occurred. Estoppel and payment of invoices The second issue before the court was whether monthly invoices rendered by HSM, and approved, certified, and paid by Aker, could be subject to later review or otherwise disputed. HSM argued that Aker were estopped from disputing that the invoice sums were properly due. The Court completely rejected this argument – giving no less than five ‘short’ reasons for doing so, along with one ‘long’ reason that considered the full factual evidence of the invoice approval process. The clearest of those reasons was found in the terms of the Contract itself. Clause 17.9 of the Contract expressly stated that “the COMPANY may correct or modify any sum previously paid” where a sum was incorrect or not properly payable, and that “[n]either the presentation nor payment or nonpayment of an individual invoice” constituted a waiver of any right.Interestingly, the judgment gives some insight as to why such an unsuccessful estoppel argument arose at all. In the course of the trial, witnesses for HSM suggested that the MOU had the result of making the contract a fully reimbursable one. However, this understanding was incorrect: although the MOU did make changes to specific elements of HSM’s remuneration to a ‘cost plus’ basis, those individual changes were identified in the MOU. The MOU did not otherwise change remuneration under the Contract. As a result of this, it was apparent that large parts of HSM’s invoices – amounting to some €20m – now disputed by Aker, might not be properly payable under the express terms of the MOU. The estoppel argument therefore only arose “because HSM belatedly realised that the MOU did not say what [they] wanted it to say.”