Witness interviews play a central role in workplace investigations. The way these conversations are conducted can directly impact the quality of findings, employee trust, and legitimacy of the investigation. .
In Australian workplaces, investigations must be fair, impartial, and defensible. Witnesses are not just information sources. They are employees who may already feel vulnerable, uncertain, or anxious about their involvement. When interviews are mishandled, the risk of flawed outcomes and ongoing workplace harm increases significantly.
Below are five common mistakes investigators make when interviewing witnesses and how they can be avoided.
1. Asking Leading Questions
One of the most frequent mistakes in witness interviews is the use of leading questions. These questions subtly guide the witness toward a particular answer, often without the interviewer realising it.
For example, asking a witness whether someone appeared angry or aggressive already assumes a behaviour that may not have been observed. This can influence the witness’s recollection and compromise the accuracy of the evidence gathered.
In the Australian context, investigations must be conducted with procedural fairness. Leading questions can undermine this by contaminating evidence and weakening the credibility of findings if challenged later.
A better approach is to use open and neutral questions. Allow witnesses to describe what they observed in their own words and avoid introducing assumptions into the conversation.
2. Credibility Bias and Perception Bias
Credibility bias occurs when an interviewer forms a judgement about a witness based on personal perception rather than the substance of their evidence. This may be influenced by factors such as the witness’s communication style, role seniority, emotional presentation, or past interactions.
Perception bias can lead to witnesses being unfairly discredited or their evidence being given less weight, even when it is relevant and consistent. For example, lending more weight to a well liked witness’ statement, or placing lower credibility based on organisational hierarchy.
Interviewers should assess credibility based on factual evidence, consistency, detail, and corroboration (if appropriate), not personality or assumptions. Structured interview frameworks and proper training can help reduce unconscious bias during investigations.
3. Lack of Organisational Support for Witnesses
Witnesses are often given minimal information about the investigation process. This can leave them feeling uncertain about their role, confidentiality expectations, and what happens after the interview. If you see increased stress levels, witness disengagement or a reluctance to participate in investigations, it pays to identify the unsaid contributing factors.
When support is missing, witnesses feel isolated or anxious, and often fear victimisation, which can affect the quality of their responses and their wellbeing.
Organisations can benefit from clearly explaining the investigation process, outline available support options such as an internal support person (HR business partner, or a manager) or Employee Assistance Programs, and provide assurance of no victimisation of witnesses to encourage participation. Giving witnesses some context around the investigation, without compromising confidentiality or creating bias also helps them come prepared during interviews.
4. Failing to Prioritise Recovery and Relationship Repair After the Investigation
Many investigations end once findings are delivered. What often gets overlooked is the impact the process has had on workplace relationships.
Witnesses may need to continue working alongside respondents or other involved parties. Without active recovery efforts, unresolved tension, mistrust, or discomfort can linger long after the investigation concludes.
In Australian organisations focused on strong workplace culture, ignoring post investigation recovery can lead to reduced morale, poor collaboration, and lack of trust .
HR teams should plan for follow up conversations, reintegration support, and where appropriate, facilitated discussions to help restore professional working relationships and rebuild trust.
5. Insufficient Protection from Victimisation and Micro Bullying
Witnesses may face subtle or overt negative treatment after participating in an investigation. This is particularly common when the complainant or respondent is a manager or senior leader.
Victimisation may appear as exclusion, changes in behaviour, controlled interactions and sarcasm, reduced opportunities, or ongoing micro bullying that is difficult to prove but deeply damaging.
Australian employment law prohibits adverse action against employees for participating in investigations. However, without active monitoring, these risks can go unnoticed.
Organisations must take proactive steps to protect witnesses by reinforcing anti victimisation policies, monitoring workplace dynamics, and providing safe channels for witnesses to raise concerns if issues arise after the investigation.
