The Rule of Collateral Finality

The nature of the rule

There are a number of rules which govern the evidence procedures in court and in particular there are ones that regulate the examination of witnesses. An example of an established practice is the rule of collateral finality, which applies to cross-examination of all witnesses in court.

The rule provides that the answers of the witness given on replies to questioning under cross-examination on collateral issues are to be taken as final. Therefore, following an answer even if it is incorrect, the party cross-examining cannot attempt to establish the contrary. Essentially they cannot use any further evidence to rebut what the witness has said. This includes either asking further questions or calling other witnesses to testify to the contrary or providing other documentary evidence to the effect.

However, it is important to emphasise that even though such restriction exists, the tribunal of fact is under no obligation to accept the answer given by the witness as true. Therefore, such would still undergo scrutiny by the fact finder in the case.

The philosophy

The reasoning behind the rule is for the courts’ time not to be wasted in establishing all issues even if they are not material to the case. It provides for focus on the essential issues of the proceedings by giving less weight on collateral matters. Further, the rule recognises it would be unfair to ambush a witness with questioning on issues that he had not anticipated.

Meaning of collateral

For the purposes of this rule, collateral issues are ones which are not directly relevant to the facts in issue of the case. In considering whether a matter is relevant to a fact in issue or not, the question to be asked is whether the information is going to the root of an issue in the proceedings.

Collateral issues could be both regarding credibility of a witness as well as establishing factual liability of the party.

Whether the issue is collateral or not is a decision to be made by the judge and it will only be interfered with by the Court of Appeal if it is wrong in principle or was clearly wrong on the facts of the case.

For example when the issue in the case concerns the whereabouts of a person in the evening in question, it would be immaterial to establish whether he took the bus in the morning or walked to work. Therefore, it would be viewed as a collateral issue and the restriction on further cross-examination would apply.

The exceptions of the rule

 There are four categories of information which form an exception to the rule of collateral finality. Those are:

  1. Previous convictions

  2. Establishing bias

  3. Reputation for untruthfulness

  4. Disability affecting reliability

Unlock this article now!


For more information on:

  • Previous convictions
  • Bias
  • Evidence of reputation to be untruthful
  • Evidence of disability affecting reliability