Imagine you're investigating a serious workplace incident.
The evidence appears to point to one employee being responsible. But when you interview them, they provide a completely different explanation for what happened.
How far do you need to go to test that explanation before making your findings?
This was a central issue in a 2025 Fair Work Commission Full Bench decision involving an experienced forklift operator who was dismissed following a serious workplace accident.
The employer believed the accident resulted from unsafe operation of the forklift. The employee maintained that the brakes had failed.
Although the employer arranged for the forklift to be inspected, it hadn't undertaken testing that could have helped determine whether the employee's explanation was correct.
The decision raises an important question for workplace investigators: when someone offers an alternative explanation, what enquiries are reasonably necessary before you can reach a defensible finding?
A serious workplace accident with two possible explanations
The employee had approximately 25 years' experience operating forklifts and worked at a manufacturing facility in New South Wales.
In June 2023, he was operating a large forklift when a metal plate fell from part of the machine.
After inspecting the component with a colleague, he decided to move the forklift to a parking area so that repairs could be arranged.
However, as he approached the parking area, the forklift failed to stop.
It travelled forward, colliding with equipment, entering a pedestrian area and eventually striking a roller door.
The incident caused extensive damage and created a serious risk of injury.
The employee maintained that he had attempted to apply the brakes, but the brake pedal had gone all the way to the floor without resistance.
He explained that, realising he couldn't stop, he deliberately steered between a boiler and another hazardous area to minimise the potential damage.
The employer reached a different conclusion.
It considered that the accident was caused by the employee operating the forklift unsafely, possibly by pressing the accelerator rather than the brake.
The employer also questioned his honesty in maintaining that the brakes had failed.
Following an investigation, the employee was dismissed.
The investigation that failed to resolve a critical question
After the accident, the employer arranged for its regular forklift servicing company to inspect the machine.
The technician reported that the brakes were functioning normally.
The forklift was subsequently returned to service, with no further reported braking problems.
These matters supported the employer's conclusion that the employee had caused the accident.
However, there was a significant gap in the investigation.
The technician hadn't tested the brake fluid for water contamination.
During the Fair Work Commission proceedings, evidence established that water contamination could potentially cause a temporary loss of braking effectiveness.
This could produce what was described as a "soft pedal", where the brake pedal loses resistance.
Importantly, the evidence indicated that the braking system might function normally again after it had cooled.
Consequently, the fact that the forklift's brakes worked when inspected after the accident didn't necessarily eliminate the possibility of an earlier temporary failure.
There were also anomalies in the forklift's service records, including uncertainty about whether all required maintenance had been undertaken.
The employee's explanation therefore had an evidentiary foundation.
It wasn't simply an unsupported suggestion raised to avoid responsibility.
The Commission considered that further testing could have assisted in determining whether water contamination had contributed to the accident.
What did the Fair Work Commission decide?
At first instance, Commissioner Matheson examined the evidence and identified two possible explanations for the accident.
The first was that the employee had failed to brake properly, perhaps because he pressed the accelerator instead or panicked after the forklift began colliding with equipment.
The second was that he had attempted to brake, but the braking system had temporarily failed.
There was evidence supporting aspects of both explanations.
However, the Commissioner considered several matters relevant to the employee's account, including:
His 25 years' experience operating forklifts.
His consistent explanation that the brake pedal had lost resistance.
The absence of evidence that he was impaired or operating the forklift erratically before the incident.
Anomalies in the forklift's maintenance records.
Expert evidence that water contamination could cause temporary brake failure.
The failure to test the brake fluid for contamination.
The Commissioner wasn't satisfied that operator error was more plausible than the employee's explanation.
On the evidence available, she couldn't be satisfied on the balance of probabilities that the employee had operated the forklift unsafely.
She also wasn't satisfied that he had acted dishonestly when explaining the accident.
Consequently, the employer hadn't established a valid reason for dismissal.
The dismissal was found to be unfair, and the employee was ordered to be reinstated with continuity of service and compensation for lost remuneration.
The employer appealed: Was it being required to disprove the employee's explanation?
The employer appealed to a Full Bench of the Fair Work Commission.
One of its central arguments was that the Commissioner had effectively required it to conclusively disprove the possibility of brake failure.
The employer argued that this incorrectly applied the balance of probabilities and the principles established in Briginshaw v Briginshaw.
The Full Bench rejected that argument.
It explained that the Commissioner hadn't imposed a requirement to conclusively disprove every competing explanation.
Rather, the Commissioner had identified that further testing could have established whether water contamination was present.
The Full Bench accepted that the shortcomings in the investigation were relevant to the assessment of the dismissal.
It also found that the Commissioner had properly assessed the evidence when determining whether the alleged misconduct had been established.
Permission to appeal was refused.
The important distinction is that the employer wasn't required to conclusively eliminate every possible explanation. However, its failure to undertake a reasonable enquiry left an important evidentiary issue unresolved.
How far should workplace investigators go?
This is where the decision becomes particularly useful for workplace investigators.
When a respondent provides an alternative explanation, the investigator needs to consider whether that explanation raises a material factual issue requiring further enquiry.
That doesn't mean investigating every hypothetical possibility.
However, where an alternative explanation is supported by evidence and could materially affect the findings, it should be properly considered.
The following principles provide a practical framework.
1. Identify precisely what the allegation requires you to establish
In the forklift case, the employer alleged that the employee had operated the machine unsafely and had been dishonest about what occurred.
The fact that a serious accident occurred was undisputed.
However, an accident doesn't necessarily establish misconduct.
The investigator needed to determine whether the employee's conduct caused the accident and whether the evidence supported a finding of dishonesty.
This distinction is important in other workplace investigations.
For example, if an employee is accused of deliberately falsifying a timesheet, establishing that the timesheet was inaccurate doesn't necessarily establish deliberate dishonesty.
The investigator needs evidence capable of supporting each relevant element of the allegation.
2. Consider whether the alternative explanation has an evidentiary foundation
A respondent may provide an explanation that is inconsistent with the available evidence or appears unlikely.
However, investigators should examine what, if anything, supports the explanation before dismissing it.
In this case, several matters supported the possibility of brake failure.
The employee had consistently maintained that the brake pedal lost resistance.
There was evidence about the effect of water contamination, and the service records contained anomalies.
The explanation therefore warranted examination.
An investigator should consider whether the respondent's explanation is supported by documents, witnesses, technical information or other relevant circumstances.
An explanation that is entirely speculative may require little further enquiry.
However, an explanation that has a reasonable evidentiary basis and could affect the outcome may warrant additional investigation.
3. Identify evidence that could help resolve the competing explanations
One of the most important aspects of this decision is that additional testing could potentially have resolved the central dispute.
The employer had access to the forklift and could have arranged testing for water contamination.
However, that testing wasn't undertaken.
The Commissioner considered this a deficiency in the investigation.
The same issue arises in many workplace investigations.
For example:
Alleged bullying: A manager is accused of deliberately excluding an employee from meetings. The manager explains that the employee wasn't involved in the relevant projects. The investigator could examine meeting invitations, project allocations and workplace communications.
Alleged dishonesty: An employee is accused of deliberately recording incorrect working hours. The employee maintains that the electronic timekeeping system was malfunctioning. The investigator could examine system records or relevant technical information.
Alleged inappropriate communication: An employee is accused of sending an offensive message. The employee says the message has been taken out of context. The investigator could obtain the surrounding communications.
In each example, the investigator should consider whether reasonably available evidence could assist in determining which explanation is supported.
4. Be careful about relying on evidence that doesn't answer the relevant question
The employer in the forklift case had evidence that the brakes worked after the accident.
At first glance, that appeared to contradict the employee's explanation.
However, the evidence about temporary brake failure meant that a later successful test didn't necessarily establish that the brakes had functioned properly during the incident.
This illustrates a common investigation problem.
Evidence may appear persuasive without directly addressing the disputed factual issue.
For example, an employee accused of workplace bullying may have received positive performance reviews.
Those reviews may be relevant background information, but they don't necessarily establish whether particular alleged incidents occurred.
Similarly, the absence of earlier complaints doesn't necessarily establish that misconduct didn't occur.
Investigators should carefully consider what each piece of evidence actually proves and whether it addresses the allegation.
5. Explain why you accept or reject the alternative explanation
An investigation report should explain how the evidence relating to competing explanations has been assessed.
If an investigator rejects a respondent's explanation, the reasoning should identify why the available evidence supports that conclusion.
For example, the report might explain that the respondent's account is inconsistent with contemporaneous records, contradicted by reliable witness evidence or unsupported by relevant documents.
Conversely, if an alternative explanation raises reasonable doubt about whether the alleged conduct occurred, the investigator should explain why the evidence is insufficient to substantiate the allegation.
The important point is that findings should be supported by a clear analysis of the evidence.
What happens when both explanations remain possible?
An investigator may reach the end of an investigation and find that two competing explanations remain plausible.
The task is then to determine whether the evidence establishes the allegation on the balance of probabilities.
The investigator isn't required to establish exactly what occurred in every respect.
However, they need to be reasonably satisfied that the particular conduct alleged occurred.
In the forklift case, the Commissioner couldn't determine whether operator error or brake failure caused the accident.
Importantly, she wasn't satisfied that the evidence established the employer's allegation of unsafe operation.
Consequently, the employer hadn't established a valid reason for dismissal based on that alleged misconduct.
This illustrates why an investigator shouldn't automatically reject an employee's explanation merely because it hasn't been conclusively proved.
The relevant question is whether the evidence supports a finding that the alleged misconduct occurred.
What about the Briginshaw principle?
The employer's appeal also raised the application of the Briginshaw principle.
The Full Bench confirmed that allegations of misconduct are assessed on the civil standard of proof: the balance of probabilities.
However, the seriousness of an allegation, its inherent likelihood and the gravity of the consequences are relevant to determining whether the evidence is sufficiently persuasive.
In this case, the allegations involved potentially life-threatening unsafe conduct and dishonesty.
The Full Bench found that the Commissioner had applied the appropriate principles in assessing the evidence.
The decision doesn't create a separate or higher standard of proof for serious misconduct.
Rather, it reinforces the need for careful evidence assessment before making serious findings.
Does every alternative explanation need to be investigated?
No.
This decision doesn't establish a general requirement to investigate every possible explanation a respondent might raise.
The appropriate extent of an investigation depends on the circumstances.
An investigator should consider the nature and seriousness of the allegation, the explanation provided, the evidence supporting it and whether further enquiries are reasonably available.
The potential significance of the evidence is particularly important.
Where an enquiry could materially affect whether an allegation is substantiated, there may be a strong reason to pursue it.
Where an explanation is unsupported, irrelevant or incapable of affecting the findings, further investigation may not be necessary.
Investigators should be able to explain why particular enquiries were undertaken and why others weren't considered necessary or practicable.
Frequently asked questions
What if the respondent's explanation seems unlikely?
An investigator can consider how plausible an explanation is, but should assess it against the available evidence. An explanation that initially appears unlikely may still be supported by documents, witnesses or other relevant information.
Can an investigator substantiate misconduct without disproving the respondent's explanation?
Yes. The Full Bench confirmed that an employer isn't required to conclusively disprove every alternative explanation. The question is whether the allegation is established on the balance of probabilities.
What if important evidence is unavailable?
The investigator should consider whether the remaining evidence is sufficient to support a finding. Any significant evidentiary limitations should be acknowledged and addressed in the analysis.
Does an inconsistent explanation establish dishonesty?
Not necessarily. An inconsistency may be relevant to credibility, but investigators need to consider its significance and whether the available evidence supports a finding that the respondent knowingly provided false information.
When should an investigator obtain expert evidence?
Expert evidence may be appropriate where the investigation involves technical or specialised matters beyond the investigator's expertise and those matters are material to the findings.
The decision illustrates how technical testing can be important where it may assist in resolving a disputed explanation.
Final thoughts
The 2025 Full Bench decision provides a useful lesson about the importance of properly considering alternative explanations in workplace investigations.
The employer believed that an experienced forklift operator had caused a serious accident through unsafe operation.
The employee maintained that the brakes had failed.
Although the employer obtained evidence that the brakes worked after the incident, it hadn't undertaken testing that could have helped establish whether temporary brake failure was responsible.
The Commission ultimately found that the employer hadn't established the alleged misconduct.
For investigators, the practical lesson is to consider whether an alternative explanation has a reasonable evidentiary foundation and whether further enquiries could materially assist in determining the allegation.
A defensible finding requires an assessment of the evidence supporting the allegation and any material evidence that may point to a different explanation.
Insight Investigations provides independent workplace investigations, reportable conduct investigations and professional training in investigation practice.
Case references: [2025] FWCFB 16; [2024] FWC 1717.