In the present case, the Prosecution contended that the Appellant had waived his right to challenge on appeal any vagueness of the Indictment in respect of the murder of Mr. Murefu as he did not object at trial to the testimony concerning that event. At para. 51, the Appeals Chamber recalled its previous finding in Niyitegeka on whether and under which conditions an appellant can raise an indictment defect for the first time on appeal:

In general, “a party should not be permitted to refrain from making an objection to a matter which was apparent during the course of the trial, and to raise it only in the event of an adverse finding against that party.” Failure to object in the Trial Chamber will usually result in the Appeals Chamber disregarding the argument on grounds of waiver. In the case of objections based on lack of notice, the Defence must challenge the admissibility of evidence of material facts not pleaded in the indictment by interposing a specific objection at the time the evidence is introduced. The Defence may also choose to file a timely motion to strike the evidence or to seek an adjournment to conduct further investigations in order to respond to the unpleaded allegation. [...]

The importance of the accused's right to be informed of the charges against him under Article 20(4)(a) of the Statute and the possibility of serious prejudice to the accused if material facts crucial to the Prosecution are communicated for the first time at trial suggest that the waiver doctrine should not entirely foreclose an accused from raising an indictment defect for the first time on appeal. Where, in such circumstances, there is a resulting defect in the indictment, an accused person who fails to object at trial has the burden of proving on appeal that his ability to prepare his case was materially impaired. Where, however, the accused person objected at trial, the burden is on the Prosecution to prove on appeal that the accused's ability to prepare his defence was not materially impaired. All of this is of course subject to the inherent jurisdiction of the Appeals Chamber to do justice in the case.[1]

In the present case, the Appeals Chamber held the following:

54. Although the Niyitegeka Appeal Judgement referred to the accused’s obligation to interpose a timely objection to a pleading defect when evidence is introduced at trial, it did so in the context of deciding whether and under what conditions it was appropriate for an appellant to challenge such a defect for the first time on appeal. This case presents a different situation. The Appellant repeatedly brought the issue to the Trial Chamber’s attention in its briefing, and the Prosecution never suggested that he had waived his objection by not raising it earlier. And the Trial Chamber actually decided the issue, albeit in the context of murder alone and not genocide. In Ntakirutimana, the Appeals Chamber recognized that where the Trial Chamber has treated a challenge to an indictment as being adequately raised, the Appeals Chamber should not invoke the waiver doctrine.[2] In light of these circumstances, the Appeals Chamber holds that the Appellant did not waive his objection to the pleading defect. It therefore remains the Prosecution’s burden to prove that the Appellant’s defence was not materially impaired by the defect.