Expert Witness Journal Issue 67 June/July 2026 - Flipbook - Page 80
These principles are embedded within the statutory
framework, including the Provision and Use of
Work Equipment Regulations (PUWER) and the
Health and Safety at Work etc. Act (HSWA). Under
these duties, employers are expected to:
•
•
•
•
•
•
Anticipate foreseeable misuse of equipment
Design out risk wherever reasonably practicable
Avoid excessive reliance on procedural controls
alone.
An engineering analysis at an early stage helps
identify all contributing factors and preserves
recovery and liability options.
In civil litigation, arguments founded solely on “user
error” are increasingly vulnerable. Such positions are
open to challenge based on contributory negligence
analysis, strict statutory duties, and expert evidence
demonstrating that the risk was foreseeable and
should have been controlled through engineering
measures.
Policy Response
Forensic engineering causation analysis frequently
informs policy response by providing clarity on:
•
Conversely, expert opinions that attribute causation
solely to operator behaviour, without examination
of the adequacy of engineering controls, are often
exposed under cross‑examination and carry reduced
evidential weight.
•
•
•
When user error is the root cause
A safe system of work does not exclude 昀椀ndings of
genuine user error. Where engineering controls
are appropriate, e昀昀ective, and properly maintained,
forensic investigation can demonstrate that the
injured party’s actions were the proximate cause
of injury. Crucially, this conclusion must be
physically evidence‑led rather than procedural or
documentation‑focused.
User behaviour is almost always present in workplace
accidents. However, it is rarely the root cause. Across
machinery, industrial, and marine environments,
forensic
engineering
analysis
repeatedly
demonstrates that injuries occur when systems fail
to adequately manage predictable user interaction.
For insurers, brokers, and legal advisers, moving
beyond default reliance on “user error” is essential
to achieving defensible liability positions, accurate
apportionment,
and
informed
commercial
outcomes. User actions provide the immediate
context for many incidents, but they are seldom
the originating cause of injury. It is the ‘system’s
tolerance of foreseeable behaviour, through design,
safeguarding, or control de昀椀ciencies, that typically
enables harm.
Key considerations include:
•
•
•
Compliance with policy conditions relating to
maintenance, inspection, and safe use
The appropriate application of policy exclusions
Allocation of liability between insured and
uninsured parties, including third‑party
contributors.
Early technical scrutiny therefore supports
both defensible coverage decisions and e昀昀ective
claims management.
Conclusion
From a forensic engineering perspective, user
error is defensible where the system is shown to be
fundamentally safe, and the behaviour leading to
injury was exceptional or unforeseeable.
•
Obscure potential third‑party liability, including
that of equipment manufacturers, installers, or
maintenance contractors
Undermine
subrogation
prospects
by
prematurely narrowing the causation narrative
Reduce leverage in liability apportionment and
settlement discussions by conceding primary
fault too early.
Engineering integrity: Con昀椀rmation that
guarding, interlocks, and safety systems
were present, compliant, and functioning as
intended, with no defects or degradation.
Foreseeability: Assessment of whether the action
was a clear deviation from normal operation
Training and instructions: Evidence that clear,
reasonable, and task‑appropriate training and
instructions were in place and aligned with
system design.
Deviation from safe systems: Identi昀椀cation of
unjusti昀椀ed change from established systems of
work, such as bypassing isolation or removing
safeguards.
Where forensic investigation establishes that
equipment was appropriately designed, safeguarded,
and maintained, and that risks were controlled
through e昀昀ective engineering measures, injury
may properly be attributed to user error. In such
cases, the decisive factor is not the mere presence
of user action, but evidence that the behaviour was
exceptional, unforeseeable, or involved deliberate
circumvention of safety systems.
Why this matters to stakeholders
References:
Claims Strategy
1. Health and Safety Executive (HSE). Safe use of work equipment
(PUWER Approved Code of Practice L22).
2. ISO 12100:2010 – Safety of machinery – General principles for
design – Risk assessment and risk reduction.
3. HSE. Reducing risk, protecting people – HSG65.
Early acceptance of “user error” as the cause of an
incident can have adverse consequences. It may:
EXPERT WITNESS JOURNAL
78
JUNE 2026
