Expert Evidence: Getting It Right After a Safety Incident

Our Corporate Crime and Investigations Team continues its 2026 series on responding to a safety incident. This month, we explore the role of expert evidence and how organisations can use experts effectively while avoiding common pitfalls.

The focus is practical: what to think about in the first hours and days after an incident, and how early decisions on expert involvement influence liability, disclosure and regulatory engagement later.

Why do experts matter in incident response?

After a serious health and safety incident, organisations often need immediate guidance. Understanding what has happened, whether the site / operation is safe and what risks remain is key. This may require technical expertise from specialists including engineers, scientists or risk experts. Advisory experts play an important role at this stage. Later, if a civil claim or criminal investigation arises, formal expert evidence can become central to how liability is determined.

Understanding the difference: advisory work versus expert evidence

Advisory expert work can happen in the immediate aftermath of a major incident. It is quick and designed to help the organisation understand the cause of the incident, manage a response to the situation, and aid decision making. These operational opinions are not intended for litigation and may be disclosable in regulatory investigations.

In criminal cases, expert evidence is governed by Part 19 of the Criminal Procedure Rules and the accompanying Criminal Practice Directions. The expert’s overriding duty is to the court. Their reports must be structured, transparent and independent. Courts are increasingly focused on whether an expert’s conclusions are supported by clear reasoning and reliable methodology. Ultimately, experts have to explain how their analysis leads to their conclusions, rather than relying on assumption or assertion. This is why separating advisory and evidential experts is now standard practice in many investigations.

Independence is an important part of expert credibility. Courts expect experts to be impartial, objective and transparent about any limitations in their knowledge.

Expert reports are most effective when they are tightly scoped, clearly structured and focused on the technical issues that require expert input. Experts should address the specific questions they have been instructed on and avoid straying into legal analysis or matters outside their expertise.

Key Considerations at the outset are as follows:

1. Identification of an Expert: Choose an expert with the right technical expertise and sufficient independence to withstand scrutiny if their evidence is later relied on in proceedings or consider instructing two different experts with clear, distinct remits.
2. Application of Privilege: Consider from the outset whether the expert’s work is being obtained for reasonably contemplated litigation so if appropriate privilege can be maintained.
3. Instructing an Expert: Define the scope of the instruction carefully so that the expert addresses the technical issues without straying into legal analysis or areas beyond their expertise.
4. Format of an Expert Report: If a report may be used in criminal or civil proceedings, it must comply with the applicable procedural rules.
5. Impact of Expert Evidence: Expert evidence can shape findings on causation, the interpretation of reasonably practicable steps, foreseeability, regulatory engagement and overall liability.

At Burges Salmon, we frequently provide training and advice to corporate clients on managing multi-stakeholder investigations. For more information or to discuss anything in this article, please contact Charlotte Whitaker in Burges Salmon’s Corporate Crime & Investigations team or sign up to our Health and Safety mailing list by clicking the link below.

If you want to read the previous article in our series, please find this included below: