Assessing the credibility of evidence

Brooke Hall
October 21, 2020
Brooke Hall

Undoubtedly one of the most frequent questions I am asked when I tell people what I do for a living, is “How do you work out who to believe?”

As investigators we are asked to make findings of fact on the balance of probabilities. In considering all of the available evidence and arriving at those findings, it is often necessary to make an assessment of the credibility of witness evidence, particularly when there are a number of different accounts about the same alleged event. In today’s blog, I’ve provided some guidance as to what factors you might consider in assessing the credibility of witness evidence during a workplace investigation.

Dubious demeanour?

One furphy to dismiss at the outset is that you are able to tell, purely by a person’s demeanour during their interview, whether or not they are being deceptive. Research tells us that the odds of being able to do this effectively are little more than 50/50.

The fact that the interviewee is sweating and turning red might be down to the temperature of the room, or nervousness, or a medical condition, as opposed to a sign that they are fibbing. Similarly, cultural differences might explain why a witness is reluctant to meet your eye, appears nervous or uncomfortable to answer your questions directly.

The dangers of imposing your own assumptions about how a ‘credible person’ would present were highlighted in the case of Wilson v Anglo Coal (Moranbah North Management) Pty Ltd T/A Anglo American [2017] FWC 4386. In that case, the internal investigator placed particular weight on the respondent’s facial expressions and demeanour when later making findings about the evidence obtained at interview.

In the investigation report, the investigator commented that the respondent ‘froze’ and looked ‘surprised and shocked’ when initially asked for his response to an allegation, and that this was ‘inconsistent’ with his later denial. As a result, she did not accept his account. It is worth noting that this was the first time that the allegations of serious sexual harassment were put to Mr Wilson.

Commissioner Spencer of the Fair Work Commission noted that the test in Briginshaw was ‘fundamentally relevant to this matter, where significant evidence has been led on issues of credibility’ and where ‘the allegations are serious, and significant consequences flow from the findings’. Overall, it was found that there was not clear and cogent evidence to substantiate the evidence in question, and that relying on someone freezing at interview was ‘an inexact proof’.

The case highlights that interview and investigations are formal processes which can be confronting and intimidating and will likely impact on a witness’ emotions and presentation during an interview. Each of us reacts differently in stressful situations and it important to be aware of your assumptions about what makes a person credible, which may well be false and could be (unconsciously) biased.

A deeper dive…

This is not to say, that a person’s demeanour is not relevant at all, rather, it is one of a number of potential factors that might be taken into account when assessing evidence. If you doubt the credibility of a participant’s evidence, during your analysis, think about what has led you to think this way. A close analysis of the person’s evidence will often provide a more objective basis for assessing the credibility of that evidence. For example,

  • Is their account internal logical and consistent with that of other witnesses?
  • Did the person provide inconsistent or changing accounts of events? Did they explain why their recollection changed? Is that explanation logical?
  • Are you able to assess the level of confidence they have in their recollection of events, as indicated by the language they use? For example, “I wouldn’t have thought Shirmaine would have yelled at a regular team meeting. I mean, she would have no reason to get upset”, is less definitive than, “I have been to every team meeting so far this year. Shirmaine has never yelled in any of those meetings. I would remember if she had, I take the minutes of the meetings, and she is usually very calm”.
  • Did they answer your questions spontaneously and openly, acknowledging when their recollection was not clear or was confused? Did they avoid answering the question altogether, telling a long-winded story addressing what should have happened, as opposed to reporting their recollection of what did?
  • Whether the phrasing of their answers indicated that they wished to sway your thinking? For example, using emotive or exaggerated observations that were not consistent with other witnesses? In contrast did they seek to downplay what they saw or heard? Consider whether there may be a motive for these inconsistencies.

Just like making findings of fact, when you make assessments about the credibility of a witness’s evidence you should expressly state this in your report, together with an explanation justifying your conclusions about the credibility of the participant’s evidence. For example, if you perceive that the witness attempted to downplay the tone and aggression of the respondent’s conduct, using examples of that in your report, will make it clear how you arrived at this conclusion.

Credibility versus reliability

It is important to remember too that humans are fallible and that in some cases, it might be that a witness is just mistaken or has a poor memory. This does not mean that the witness is necessarily untrustworthy, just that their recollection of the event is poor. You might then decide that their evidence is not as reliable as other accounts, rather than conclude that the witness is being dishonest.

This distinction is particularly important if after considering all of the evidence, you decide you prefer the evidence of the respondent on the basis that it is more credible than the complainant’s evidence.

As noted above, you should always explain your findings about the credibility of parties in your report. It’s also important to emphasise though, that just because a complainant’s complaint is not made out on the balance of probabilities, it doesn’t necessarily follow that the complaint had no basis at all. One person’s perception of events may not be the reality, however, it is quite another question (for another separate investigation) to discover if a complaint was vexatiously made.

Workplace Investigations Book, 3rd Edition !

Worklogic is thrilled to announce that the third edition of Workplace Investigations published by Wolters Kluwer is now available for purchase!

As part of our celebration of the launch of our third edition, we are running a four-part series, “Meet the Authors”. In each of these short audio chats, we are taking a deep dive into some of the hot topics in the latest edition.

In the third audio chat Rose Bryant-Smith discusses learnings from recent cases relating to the conduct of workplace investigations. You can listen to it here.

About Brooke Hall

Brooke Hall has significant experience in the workplace relations area, having previously worked as a lawyer for 10 years at the now Fair Work Ombudsman. Brooke brings strong communication, investigative and analytical skills in the area of dispute resolution to Worklogic. Her strong client service focus and pragmatic approach ensures clients receive practical solutions to a range of workplace issues.

Worklogic has extensive experience in triaging and resolving workplace complaints.  If you would like advice on a workplace complaint, you can contact Brooke for an obligation-free discussion via email or by calling (03) 9981 6500.

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