Investigating worker-to-worker claims: control, causation and liability

Worker-to-worker (W2W) claims arise when a person – typically employed by one entity – is injured on a worksite due to the negligence, acts or omissions of another entity during the course of employment.

These claims occur across many industries, including construction, logistics, manufacturing, healthcare, hospitality and labour hire. While every claim turns on its own facts, successful investigations consistently focus on three key issues: control, causation and liability.

Control: The central issue

Determining who exercised control is fundamental to assessing liability in W2W claims. However, this is rarely straightforward.

Modern worksites often involve multiple parties, including host employers, principal contractors, subcontractors, labour hire providers and individual workers. Responsibilities frequently overlap, making it difficult to determine:

• Who controlled the injured worker
• Who controlled the system of work
• Who controlled the plant, equipment and site conditions

Although control appears to be a simple concept, identifying where it truly sat at the time of the incident requires careful investigation.

The key questions

Every W2W investigation seeks to answer two critical questions:

1. Who was at fault (or most at fault)?
2. Who exercised the greatest degree of practical control?

To answer these, adjusters must determine:

• What duties of care were owed, and by whom
• Whether those duties were breached
• Which party (or parties) were responsible for those breaches
• Whether reasonable safety measures were implemented
• Whether any conduct fell below the required standard

Before liability can be apportioned, causation must first be established.

The non-delegable duty of care

A key legal principle underpinning W2W claims is the employer’s non-delegable duty of care.

An employer cannot transfer its responsibility for worker safety simply because another party performs the work. Employers remain responsible for providing a safe system of work by:

• Minimising foreseeable risks
• Training and supervising workers
• Enforcing safe work practices

This duty extends beyond documented policies. Employers must actively ensure worksites are safe, systems of work are effective and workers are adequately trained, supervised and protected.

What adjusters look for

In practice, investigations focus on what actually occurred — not simply what was documented.

When assessing whether an employer discharged its duty of care, adjusters consider:

• Whether the site was inspected regularly
• The quality and frequency of those attendances
• Whether supervisors actively engaged with workers on safety matters
• Whether safe systems of work were monitored and enforced

Attendance alone is insufficient. Employers are expected to observe, question and intervene where necessary.

Adjusters also assess the employer’s knowledge of hazards, their ability to influence site conditions and whether they took reasonable steps to manage foreseeable risks. These factors are critical in determining whether duty of care has been met.

Risks for host employers

Where a host employer exercises significant operational control over the site or system of work, their exposure to liability often increases.

Common risks include:

• Control of day-to-day operations
• Delayed notification of claims or recovery actions, sometimes years after the incident
• Loss or degradation of critical evidence over time
• Contractual provisions that may shift responsibility

Courts have also recognised that host employers may owe labour hire workers a duty of care similar to that owed to their own employees.

The importance of early and thorough investigations

Timely investigation is critical. Delays can lead to unavailable witnesses, faded or unreliable recollections, lost documentation and evidentiary gaps that make liability difficult to determine.

Early investigations preserve evidence and provide a more accurate understanding of how the incident occurred.

Adjusters typically review:

• WHS systems and procedures
• Risk assessments and hazard identification
• Training protocols and records
• Which party implemented and enforced safe systems of work

Courts consistently emphasise that documented policies and processes alone are not enough. Those exercising control must actively train, supervise and enforce safe work practices.

Taking a structured approach

Effective investigations extend beyond the immediate incident and examine the broader circumstances.

This includes considering:

• What happened and how
• When and where the incident occurred
• Who was involved (directly and indirectly)
• Why the incident occurred

Adjusters also assess the roles and responsibilities of each party, the condition of the site and whether other parties contributed to the incident.

Case study: Crane dismantling incident

A recent investigation demonstrates why practical control often determines liability.

The incident

A contractor was struck by overhead crane cables while dismantling a crane.

Parties involved

• Principal contractor (the Insured)
• Crane company and operators
• Injured worker
• Worker’s employer

Key findings

The investigation identified several failures before work commenced:

• A Safe Work Method Statement (SWMS) was provided only 30 minutes before work began
• The principal contractor allowed work to proceed without reviewing the crane operator’s SWMS
• No coordinated safety briefing occurred
• No exclusion zones were established
• Communication between parties was inadequate

Outcome

Although contact with overhead cables caused the injury, the investigation found the root cause was the failure to implement a coordinated and effective safe system of work.

Responsibility rested primarily with the principal contractor because it exercised practical control over the site.

This case reinforces an important principle in W2W claims: liability often follows the party that controls the work environment in practice

Considering the injured worker’s conduct

The conduct of the injured worker may also influences liability.

Investigations consider whether the worker:

• Contributed to the incident
• Failed to follow instructions or procedures
• Acted without reasonable care

These factors may affect the apportionment of liability.

It is equally important to determine the worker’s status, such as whether they were:. an employee, labour hire worker or independent contractor. In some circumstances, a contractor may effectively function as an employee, which can have implications for insurance coverage under a public liability policy.

Contracts and Insurance

Contracts play a significant role in W2W claims.

Adjusters typically examine:

• The contractual relationships between parties
• Responsibility for supervision, training, and workplace safety
• Indemnity and liability clauses
• Insurance and co-insurance arrangements

Policy terms, exclusions and conditions are also reviewed to determine the scope of available coverage.

Final thoughts

Worker-to-worker claims are often inherently complex because they involve multiple parties, overlapping duties and often competing accounts of what occurred.

However, by focusing on practical control, causation and the implementation of safe systems of work, adjusters can develop a clear and defensible view on liability.

Ultimately, W2W claims reinforce a consistent legal and practical principle: responsibility follows control – and control must be actively exercised, not merely assumed.

Connect with our liability experts to learn more about worker-to-worker claims.