What Proof Do You Have? Navigating the Balance of Probabilities in Workplace Investigations

In the UK, workplace investigations will typically involve an assessment of whether, on the evidence available, certain facts can be shown to have happened on “the balance of probabilities”. This is a standard of proof that is less stringent than "beyond reasonable doubt", which is usually reserved for determining culpability under criminal law. Essentially,it requires the investigator to be satisfied that an event is more likely than not to have occurred.

Here's how this standard plays out in practice:

1. Understanding the Standard:

In simple terms, the balance of probabilities means that if there's more than a 50% chance that something happened, the relevant facts are considered to be proven.  It does not require an investigator to be certain (or even almost certain) that a given fact is true – but simply that the evidence leans more towards one way than another. For understandably public policy reasons, this is not sufficient in criminal cases, given the potential implications of a conviction for the accused. However, it This is a fundamental benchmark for assessing evidence in civil matters, including employment disputes.

2. Application in Investigations:

Gathering Evidence: Investigators must collect all relevant evidence, understanding that even circumstantial evidence can contribute to their assessment of the probability of an event have occurred or not.  In many cases, there will be a direct conflict in witness evidence – where one witness is adamant that something happened and another witness denies it (or maintains that something else happened).  In such circumstances, assessing the credibility of each witness becomes crucial. Investigators assess not just what is said but how it's said, considering factors like consistency with other witness evidence and supporting documents, corroboration from other sources, and even the demeanor of the witness.

In some instances, the investigator may not be able to decide between two (or more) conflicting versions of events – in which case a given fact simply cannot be proven “on the balance of probabilities”. However, they should make reasonable efforts where possible to identify other evidence that might allow them to resolve what might appear to be a 50-50 call. 

Ensuring the investigation remains impartial is paramount. The balance of probabilities requires a neutral assessment of evidence, which can be challenging in workplace settings where an internal investigator might not have the relevant experience to make a finely-calibrated judgement on conflicting evidence (and explain their reasoning cogently) and/or may be perceived to be biased. In such cases, it may be appropriate to instruct a third party external investigator. 

3. Legal Implications:

Employment Tribunals: If a case goes to an employment tribunal, the tribunal will apply the same balance of probabilities test. However, how this standard is applied can vary based on the nature of the allegations (and, because we are all human, the personal interpretation of the employment judge and any lay members). For instance, in cases involving serious misconduct or discrimination, the tribunal must take great care to avoid their assessment of the evidence being influenced either by sympathy for the claimant’s view on their alleged treatment  or the potential consequences of an adverse decision for the respondents or any individual witnesses. 

Investigators must adopt a similarly rigorous approach. The focus is always on the pure facts and what is more likely than not to be the truth.

Our expert employment law solicitors all have many years’ experience advising individuals who are in your position. We will be able to guide you through the process and to help you secure the best possible outcome.

We offer a range of services, so please contact our friendly customer services team to discuss further via hello@kilgannonlaw.co.uk or 0800 915 7777.

This article is for information purposes only and is correct at the time of publication. It does not constitute legal advice 13.07.24