“The common law duty of procedural fairness does not, in my opinion, require the board to hold an oral hearing in every case where a determinate prisoner resists recall, if he does not decline the offer of such a hearing. But I do not think the duty is as constricted as has hitherto been held and assumed. Even if important facts are not in dispute, they may be open to explanation or mitigation, or may lose some of their significance in the light of other new facts. While the board’s task certainly is to assess risk, it may well be greatly assisted in discharging it (one way or another) by exposure to the prisoner or the questioning of those who have dealt with him. It may often be very difficult to address effective representations without knowing the points which are troubling the decision-maker. The prisoner should have the benefit of a procedure which fairly reflects, on the facts of his particular case, the importance of what is at stake for him, as for society.”