“It is simply the law of contract. If two persons agree that the price of the property should be fixed by a valuer on whom they both agree, and he gives that valuation honestly and in good faith, they are bound by it. Even if he has made a mistake they are still bound by it. The reason is because they have agreed to be bound by it. If there were fraud or collusion, of course, it would be very different. Fraud or collusion unravels everything.”
“It does not follow, however, that because the court will intervene to correct a decision-maker who has gone outside his authority, it will declare in advance what the limits of that authority are. The reason for this reluctance is not one of substantive law but procedural convenience. It is because in advance of the decision, the true meaning of the principles upon which he has to decide is usually a hypothetical question. It is hypothetical because it will only become a live issue if one of the parties think that the decision-maker has got it wrong. It is always possible that he may get it right and therefore wasteful and premature to come to the court until he has made his decision. The practice of the courts is not to decide hypothetical questions: see R Barnato[1949] Ch 258 .”
“There is an essential distinction between judicial decisions and expert decisions, although the reason for the distinction has been variously expressed. There is no useful purpose in phraseology such as "quasi judicial" or "quasi arbitral" as Lord Simon made plain in Arenson and although the use of the word "expert" is not conclusive, the historic phrase "acting as an expert and not as an arbitrator" connotes a concept which is clear in its effect. A person sitting in a judicial capacity decides matters on the basis of submissions and evidence put before him, whereas the expert, subject to the express provisions of his remit, is entitled to carry out his own investigations, form his own opinion and come to his own conclusion regardless of any submissions or evidence adduced by the parties themselves. Although, contrary to what is said in some of the authorities, there are many expert determinations of matters where disputes have already arisen between the parties, there is a difference in the nature of the decision made and as Kendall points out in paragraph 1.2, 15.6.1. and 16.9.1. the distinction is drawn and the effect spelt out, namely that there is no requirement for the rules of natural justice or due process to be followed in an expert determination in order for that determination to be valid and binding between the parties.”