Most practitioners miss several subtle but high-impact features of the Act.
First, the PCBU definition in s 5 is extraordinarily broad and captures many arrangements that traditional "employer" tests would miss. A labour hire company, a franchisor exercising significant control, a principal contractor on a construction site, and even a volunteer association that employs even one person can all be PCBUs. The "capacity to influence and control" test in s 16(3) means that a PCBU cannot simply rely on contractual indemnities or "it's the contractor's problem" arguments. Courts look at practical influence, not just legal title. A common error is assuming that because a contractor has its own safety system, the principal's duty is discharged. The duty is non-delegable in substance.
Second, officer due diligence (s 27(5)) is personal and ongoing. It is not satisfied by attending a one-day training course or relying on annual reports. The verification element (s 27(5)(f)) requires active checking that systems are actually working, not merely that they exist on paper. In practice, this means officers should be able to demonstrate site visits, review of incident reports, questioning of safety managers, and consideration of leading and lagging indicators. The "but I relied on management" defence is weak unless the officer can show they had reasonable grounds for that reliance and still verified key controls.
Third, the "reasonably practicable" test in s 18 is not a general balancing exercise. The structure is hierarchical: likelihood and degree of harm are considered first, then knowledge, then availability and suitability of controls, and only then cost (and only whether the cost is grossly disproportionate). Many improvement notices are successfully defended by showing that the regulator failed to address this sequence. Conversely, duty-holders frequently err by jumping straight to cost.
Fourth, the HSR powers in s 68 are stronger than many realise. An HSR does not need to be "reasonable" before issuing a provisional improvement notice or directing cessation of work (provided the training requirement in s 90(4) or s 85(6) is met). The PCBU's obligation to allow the HSR to spend "such time as is reasonably necessary" (s 70(2)) includes paid time and cannot be limited by industrial instruments. The immunity in s 66 is broad and protects good-faith acts even if they cause economic loss.
Fifth, the prohibition on insurance against penalties (s 272A) is absolute and extends to "other indemnity". Many directors and officers (D&O) policies contain carve-outs or "advancement of defence costs" clauses that may inadvertently breach this. The personal liability of officers for corporate breaches of s 272A (s 272B) adds teeth. Insurers and brokers often fail to appreciate that a policy that reimburses a fine is itself an offence.
Sixth, the mutual notification obligation in s 39A is overlooked. Both the PCBU and the person with management or control of the workplace must notify each other immediately upon becoming aware of a notifiable incident. This can create practical difficulties on multi-employer sites where the PCBU and site controller are different entities.
Seventh, the corporate culture provision in s 244B(1)(c) for fault elements other than negligence is rarely understood. It allows conviction even if no individual officer or senior manager held the relevant fault element, provided the prevailing attitudes, policies or practices within the organisation (or the relevant part of it) directed, encouraged, tolerated or led to the conduct. This is a significant expansion of liability and has been used in other harmonised jurisdictions to prosecute large corporations where safety was treated as a "paper exercise".
Eighth, the two-year limitation period in s 232 runs from when the regulator "first becomes aware" of the offence, not from the date of the incident. In complex cases involving latent injuries or delayed reporting, this can significantly extend the prosecutorial window. Conversely, the one-year extension following a coronial report (s 232(1)(b)) is often missed by defence practitioners.
Ninth, the prohibition on levying workers for safety equipment or training (s 273) is absolute. Many labour hire arrangements and "cost recovery" clauses in contracts inadvertently breach this.
Finally, the Act's interaction with the Fair Work Act is more complex than it appears. While WHS entry rights are separate, a union official who exercises a WHS entry right while also pursuing an industrial agenda may be found to have acted for an "improper purpose", exposing them to revocation of the permit (s 138) or civil penalties.
These "gotchas" explain why many organisations that believe they are compliant still receive improvement or prohibition notices, or worse, face category 1 prosecutions. The Act rewards genuine, verifiable safety leadership and punishes systems that look good on paper but do not work in practice.