23. [...] [T]he maxim expressio unius est exclusio alterius[...][1] [...] must always be applied with great care in statutory interpretation, for it is not of universal application. [...]

7. The certificate given by the Trial Chamber pursuant to Rule 73(C) (as it then stood)^[[1]^] – that it was appropriate for the continuation of the trial that an interlocutory appeal be determined – related only to [one of several] issues […]. It is, however, within the discretion of the Appeals Chamber to determine also other, related, issues where it considers it appropriate to do so, at least where they have been raised in the interlocutory appeal and the respondent to the appeal has had the opportunity to put his or its arguments in relation to those related issues. […]

19. […] Equality of arms is a broad concept that constitutes an inherent element of a fair trial. According to the principle of equality of arms each party must be afforded a reasonable opportunity to present his case under conditions that do not place him at a disadvantage vis-à-vis his opponent. It is a protection afforded to the accused to ensure that he is given procedural rights equal to those of the Prosecution in the course of criminal proceedings. Those procedural rights include giving the accused effective ways to challenge evidence produced by the Prosecution.

20. The principle of "equality of arms" inheres in the requirement that the accused be recognised the right to a fair trial. Basically, this principle embodies the notion that the accused should be afforded procedural equality with respect to the Prosecution. Its purpose is to give each party equal access to the processes of the Tribunal, or an equal opportunity to seek procedural relief where relief is needed.[4] The right to equality of arms does not include a right to equality of relief.[5] […]

15. […] Rule 7 (“Authentic Texts”) provides that the English and French texts of the Rules are equally authentic.  In the case of a discrepancy, the Rule requires the version which is “more consonant with the spirit of the Statute and the Rules” to prevail, but this provision would normally be applied only where the discrepancy between the two versions is intractable. […]

16. Although neither the Tribunal’s Statute nor its Rules of Procedure and Evidence are, strictly speaking, treaties, the principles of treaty interpretation have been used by the Appeals Chamber as guidance in the interpretation of the Tribunal’s Statute, as reflecting customary rules.[1]  Such principles may also be used appropriately as guidance in the interpretation of the Tribunal’s Rules of Procedure and Evidence. […]

3. The prosecution accepts, correctly, that the decision of a Trial Chamber as to whether two or more crimes should be joined in the one indictment pursuant to Rule 49 of the Rules of Procedure and Evidence (“Rules”) is a discretionary one.[1] A Trial Chamber exercises a discretion in many different situations – such as when imposing sentence,[2] in determining whether provisional release should be granted,[3] in relation to the admissibility of some types of evidence,[4] in evaluating evidence,[5] and (more frequently) in deciding points of practice or procedure.[6]

4. Where an appeal is brought from a discretionary decision of a Trial Chamber, the issue in that appeal is not whether the decision was correct, in the sense that the Appeals Chamber agrees with that decision, but rather whether the Trial Chamber has correctly exercised its discretion in reaching that decision. Provided that the Trial Chamber has properly exercised its discretion, its decision will not be disturbed on appeal, even though the Appeals Chamber itself may have exercised the discretion differently. That is fundamental to any discretionary decision. It is only where an error in the exercise of the discretion has been demonstrated that the Appeals Chamber may substitute its own exercise of discretion in the place of the discretion exercised by the Trial Chamber.

5. It is for the party challenging the exercise of a discretion to identify for the Appeals Chamber a “discernible” error made by the Trial Chamber.[7] It must be demonstrated that the Trial Chamber misdirected itself either as to the principle to be applied, or as to the law which is relevant to the exercise of the discretion, or that it has given weight to extraneous or irrelevant considerations, or that it has failed to give weight or sufficient weight to relevant considerations, or that it has made an error as to the facts upon which it has exercised its discretion.[8]

6. In relation to the Trial Chamber’s findings of fact upon which it based its exercise of discretion, the party challenging any such finding must demonstrate that the particular finding was one which no reasonable tribunal of fact could have reached,[9] or that it was invalidated by an error of law. Both in determining whether the Trial Chamber incorrectly exercised its discretion and (in the event that it becomes necessary to do so) in the exercise of its own discretion, the Appeals Chamber is in the same position as was the Trial Chamber to decide the correct principle to be applied or any other issue of law which is relevant to the exercise of the discretion. Even if the precise nature of the error made in the exercise of the discretion may not be apparent on the face of the impugned decision, the result may nevertheless be so unreasonable or plainly unjust that the Appeals Chamber is able to infer that the Trial Chamber must have failed to exercise its discretion properly.[10] Once the Appeals Chamber is satisfied that the error in the exercise of the Trial Chamber’s discretion has prejudiced the party which complains of the exercise, it will review the order made and, if appropriate and without fetter, substitute its own exercise of discretion for that of the Trial Chamber.[11]

CONSIDERING […] that the obligation of Counsel not to disclose the name of protected witnesses or the content of protected material is […] implicit in his or her responsibility as Counsel, and that this obligation underlay any order of a Chamber rendered pursuant to Rule 75;

9. [...] [R]equirement in Rule 28(B) that the duty Judge is to be “available at all times, including out of normal Registry hours, for dealing with applications pursuant to paragraphs (C) and (D)”. Rule 28 thus necessarily contemplates that the duty Judge will have power during normal Registry hours to deal with applications in cases which have already been assigned to a Trial Chamber. Rule 28(D) must be interpreted in a way which will correspond with what is clearly intended by Rule 28(B). It is therefore necessarily implicit in Rule 28(D) that the Judge will deal during normal Registry hours with applications which have already been assigned to a Trial Chamber. Rule 28(B) gives to the judge the discretion to refuse to do so where the application is not urgent. The exercise of that discretion will depend upon whether the application is of such a nature that it is appropriate that it be dealt with by the duty Judge rather than by the Trial Chamber to which the case has been assigned. This situation would usually arise during the official court recesses, but it would also arise where the Trial Chamber is, for reasons other than a court recess, not available to deal with the application.

10. The obvious example of where it would be appropriate – indeed, necessary – for the duty Judge to exercise the powers of the Trial Chamber (whether or not the relief sought should be granted) is where the application is an urgent one which cannot await for its resolution the return of the Trial Chamber to which the case is assigned. Another obvious example of where it would be at least appropriate for the duty Judge to exercise the power to deal with the application (again, whether or not the relief sought should be granted) is where it is an application pursuant to Rule 127 to enlarge the time prescribed by the Rules for the doing of an act, and where the time for doing that act expires during the unavailability of the Trial Chamber by reason of the court recess or other reason, or very shortly thereafter. In considering whether it is appropriate for the duty Judge to deal with any particular matter, it is important to keep in mind that the Trial Chamber will usually be in a better position to deal with a matter which requires detailed knowledge of the case.

[...]

14. Where a case has already been assigned to a Trial Chamber, urgency would usually be established where the subject matter of the application is of such a nature that the relief sought can only be granted if the application is determined at a time before that Trial Chamber is available to determine it, and where the applicant would suffer significant prejudice if the application is not determined within that time. The circumstances which could constitute urgency in any particular case cannot be precisely defined in advance. [...]

[...]

17. [...] Where an application is made in a case assigned to a Trial Chamber, but the Trial Chamber is not available to deal with it so that it comes before the duty Judge, and where that Judge correctly refuses to deal with that application because he or she has not been satisfied that it was urgent, the only ruling which should or could be made by that Judge is to refuse to deal with that application as the duty Judge. It would then be left to the Trial Chamber to deal with the application when the Trial Chamber is available to do so. This would appear to be so whether the application is addressed to the Trial Chamber or to the duty Judge directly. If the application is dismissed by the duty Judge, the Trial Chamber would necessarily be prevented from dealing with it in the ordinary course. That is not the intention of Rule 28.

13. The duty Judge’s decision as to whether to deal with an application out of normal Registry hours is a discretionary one once the Judge is satisfied as to its urgency.[1] […] [T]he finding of fact as to whether the matter is or is not urgent is, however, the same as any other finding of fact. The finding by the duty Judge that there was no urgency in the Appellant’s application cannot be reversed on appeal unless it is one which no reasonable tribunal of fact could have reached.[2] This is so whether the finding related to the application being dealt with out of, or during, normal Registry hours.

4. In the opinion of the Appeals Chamber, Rule 111 requires an appellant to identify in the Appellant’s Brief the authorities upon which he or she relies for the arguments put forward by name and citation (including the relevant page or paragraph of those authorities) only. A Book of Authorities is produced only in order to assist the Appeals Chamber in its consideration of the appeal. It is not an appendix to a party’s Brief. Provided that the Book of Authorities does not contain any legal or factual arguments, and contains only source materials, its length is not limited by any of the provisions of the Practice Direction. However, parties should include within it only those authorities to which they believe the Appeals Chamber will need to refer. It is not usually necessary to include within a Book of Authorities copies of decisions of the Tribunal itself.

13. A Trial Chamber may nevertheless always reconsider a decision it has previously made, not only because of a change of circumstances but also where it is realised that the
previous decision was erroneous or that it has caused an injustice.[1]  Where such a decision is changed, there will be a need in every case for the Trial Chamber to consider with great care and to deal with the consequences of the change upon the proceedings which have in the meantime been conducted in accordance with the original decision.