The core of the challenge is explained in the following passage of the Court of Appeal's decision:
It is now said that, despite Mr Cope's agreement to the way matters proceeded, there was in fact no power on the part of the disciplinary tribunal to permit one of its members to depart during the hearing and then take part in the remainder of the hearing. It is also said that there was a breach of the rule of natural justice that "he who decides must hear" and that that breach was not waived. All proceedings after 5.00 p.m. on 18th December 2009 were therefore a nullity including the decision of the tribunal that the charge was proved.Longmore L.J. reviewed the tribunal's authorizing provisions and concluded that the practice of temporarily absenting oneself was not prohibited. The key issue, though, was whether the absence led to unfairness.
As a general matter, tribunal members should be present for the totality of a hearing. Reviewing the transcripts afterward is insufficient:
- The judge (para 72) did not find it easy to draw any general conclusion from these authorities; she thought that the principle that "he who decides must hear" had been strictly applied in criminal cases and in cases with juries but had been more flexibly applied in civil cases without a jury. I agree with that and would myself add that in professional disciplinary cases the tribunal is, subject to the relevant bye-laws or other rules, master of its own procedure. If there is a hearing with live witnesses giving their evidence orally, it will normally be a breach of rules of natural justice for a member of the tribunal (in the absence of agreement) to absent himself while a witness is giving evidence and later return to participate in the decision. This will not normally be cured by the absent member reading a transcript of the evidence given in his absence, unless the evidence is comparatively uncontroversial for the reasons given by Lord Griffiths in Ng v The Queen. Such absence will be difficult (if not impossible) to justify if the evidence being given is that of the defendant or respondent to the disciplinary proceedings.
- I would therefore reject Mr Hamer's argument that, if any breach of natural justice occurred, it could not be waived. I would go further and say that a breach of the rule of natural justice of the kind that is said to have occurred in the present case is at most an irregularity that could be waived. Indeed if there was an agreement to the procedure adopted, I would prefer to say that there has been no breach of the relevant rule of natural justice at all. One must look at the position as it was at about 5.00 p.m. on Day 4 when Mr Mander left; if one does that, it is odd to say that the tribunal acted in breach of the rule of natural justice when all parties agreed to the course that was to be taken. "Waiver" is more naturally used in respect of something that was definitely a breach when it occurred but is later agreed not to matter.(my emphasis)
- The underlying reason of principle for not analysing the second type of case as a waived breach, primarily flows from another inherent quality of the principle entitling a person to a fair hearing. It is the recognition that denying a person a fair hearing is a wrong that is personal to that person so that, although the principles of natural justice are part of our public law and although those not directly affected or not affected at all are generally accorded standing to challenge a decision that is flawed in public law terms, this is not the case where the breach is of the audi alteram partem principle. Moreover, although there have been statements that waiver is not always possible in natural justice cases (see e.g. Mayes v Mayes  1 WLR 679 at 684 Sir Jocelyn Simon P), that is a minority view. Even after a serious breach, including the rule automatically disqualifying a person on the grounds of pecuniary interest to which I have referred (see Locabail (UK) Ltd v Bayfield Properties Ltd.  QB 431 at ) waiver is possible provided it is done so freely and in full knowledge of the facts by the person affected, and there is no other interested party affected who (as in R v Hnedon R.D.C. ex parte Chorley  2 K.B. 696) objects.
- More broadly, the requirements of natural justice have often been described as "fair play in action": see, for example, Lord Morris of Borth-y-gest in Wiseman v Borneman  1 AC 297 at 309. Particularly since the re-invigoration of the principles almost 50 years ago in Ridge v Baldwin  AC 40, the concept of fairness embodied in the different strands of natural justice has been seen as flexible and as not requiring the courts to lay down over rigid rules: see R v Monopolies and Mergers Commission, ex p. Matthew Brown Plc  1 WLR 1235 and Lloyd v McMahon  1 AC 625 at 702. One example of that flexibility is as to what precisely is required for a procedure to be fair: see, for example, McInnes v Onslow-Fane  QB 617, at 630. Regarding a procedure which has been freely accepted in advance and with full knowledge of the facts as a breach of natural justice which has been waived is in my judgment both contrived and inconsistent with the flexibility in the concept and with the idea that a procedure which breaches the rules is "unfair" and that the rules reflect the idea of "fair play in action". It in effect would create a category which might be characterised as a technical breach of natural justice, but, as Bingham LJ stated in R v Chief Constable of the Thames Valley Police, ex p Cotton  IRLR 344, there can be no such thing "because … a procedure must in all the circumstances of a given case be either fair or unfair".