We examine the rules of evidence which should be followed to improve the chances of successfully defending against a claim.
What are the rules of evidence as a whole?
The most important rule for workplace investigations is whether the evidence to be presented is relevant to the matters at issue. As the decision of Robinson v Goodman  FAC 893 demonstrates, this is determined by considering whether the evidence is of such relevance as to be “important or of consequence”. In other words, it should “affect the probability of the existence, or non-existence, of a fact in issue”.
The principle of hearsay evidence is also important to workplace investigations, as is the introduction of tendency evidence.
Hearsay relates to information obtained via rumour or through a second party. In a courtroom setting, information is deemed to be hearsay in virtually any circumstance where it has not been directly conveyed to the person testifying about it. In the investigatory setting, any hearsay evidence can be damaging to the weight placed on that evidence or testimony as a whole.
Tendency evidence considers whether past behaviour should be used to prove the current matters in question. When determining whether to rely on tendency evidence, it is important to weigh up the potential advantage against the possibility of causing damage to an accused by suggesting that their past behaviour dictates their future behaviour.
Why do the rules of evidence matter?
Any workplace investigation should be conducted having regard to the possibility that the matter could end up in the Fair Work Commission or a court. In the event that this occurs, any investigation which has clearly failed to observe basic rules of evidence may result in an adverse finding against the employer.
If an investigation relies on evidence that is ultimately inadmissible, then the employer might find itself in a position where it cannot back up its defence in any way which the commission or a court will take into account.
An additional factor to be taken into account is the Briginshaw principle. This notes that, depending on the seriousness of any given allegation, the strength of the evidence required to establish proof may change. This means that a tribunal must be satisfied, on the balance of probabilities, that the information before it and on which it is being asked to decide is based on clear, cogent and strict evidence.
The requirement for a matter to be determined on the balance of probabilities is reaffirmed in section 140 of the Evidence Act 1995 (Cth).
The importance of following the rules of evidence in workplace investigations cannot be understated. All investigators should consider these rules when collecting and analysing evidence that arises from a workplace matter.
WISE investigators are experts in the field, and with years of experience in undertaking even the most complex workplace investigations, are able to ensure your investigation is fair and legally sound. If your organisation needs assistance with a workplace investigation, WISE provides full as well as supported investigation services.