In preparation for arbitration, employers are advised they will be required to have witnesses available to testify. As the arbitration is a legal process, the Commissioner appointed will be required to decide on a balance of probabilities which version of events is more likely and who to believe.

The general rule is that the opinion of a witness is irrelevant because it is a function of the court to draw inferences and form its opinion from the facts. Witnesses are required to confine themselves to giving testimony as to the facts, and a court will form its opinions regarding those facts.

Only evidence that is relevant to the matter and issues in dispute should be led. It has been held that evidence is relevant if it is probative or disapprobative of an issue that requires proof. At arbitration, issues in dispute are usually narrowed at the commencement of arbitration or limited at a pre-arbitration conference.

Opinion evidence can be defined as an inference, impression, conclusion, or belief that a witness gives in support or opposition of an issue in contention. It is inadmissible unless given by an expert or a person who testifies from his or her observation. It may either be a layperson or an expert who testifies. Whether the evidence will be deemed admissible will depend on whether it is relevant and whether it can assist an arbitrator in deciding a fact-in-issue.

The opinion of a layperson is only relevant and admissible on certain issues that fall within the competence and experience of laypersons generally. These persons may be in a better position to draw inferences for reasons such as extended work experience in a particular field.

If expert evidence is given, it should first be established that the witness is an expert in the relevant field. Expert evidence must be relevant and be confined to issues which the arbitrator cannot determine without the help of the expert.

In IO Tech Manufacturing (Pty) Ltd and Others v Gallager Group Ltd and another (2014) 2 ALL SA 134 (SCA), the court confirmed the principle that the opinion of an expert is admissible because it is based on special prior knowledge and skill in a particular subject. Therefore, the opinion of an expert may be necessary to prove or disprove issues which are more intricate, technical and related to the field of study with which an arbitrator would not be familiar.

An arbitrator may consider the following principles to determine whether the opinion of an expert is admissible. These principles are discussed in Holtzhausen v Roodt 1997 (4) SA 766 (W) and referred to in subsequent case law.

  1. The expert witness must be called to give evidence on matters which require specialised skill or knowledge;
  2. The expertise of the witness should not be overstated to such an extent that the courts own capabilities and responsibilities are disregarded;
  3. The witness must be a qualified expert with sufficient skill;
  4. The facts upon which the expert opinion is based must be proved by admissible evidence and not based on hypothetical scenarios (the expert must give reasons for his/her opinion);
  5. The guidance offered by the expert must be sufficiently relevant to the issues raised in the matter;
  6. Opinion evidence must not usurp the function of the court, and a witness should not give an opinion of legal issues which are designated for the court to decide.

Rule 37A of the CCMA rules requires a party intending to call an expert witness, to give seven (7) days prior to the hearing, notice thereof to the commission and other party to the dispute. In addition to the notice to use an expert witness, the party is required to provide a summary of the proposed evidence of the witness and any documents the witness intends to rely upon.

The notice must also include the basis upon which the witness is considered to be an expert. The aim of this rule is to prevent delays in the arbitration process.

In summary, the “Ultimate issue doctrine” states that only a court, and not a witness, can express an opinion about an issue in dispute. However, opinion evidence can be admissible if it may assist a court or commission in determining an issue as it is no longer unneeded and has probative value.  Assuming opinion evidence is admitted, it must be considered and assessed together with direct evidence presented at the hearing.

Article by: Gordon Flanagan
Dispute Resolution Official – Cape Town