Understanding Estoppel in Workers Compensation Claims

Estoppel is a legal doctrine to the effect that a person is barred from denying the truth of a fact that has already been settled. 

In this article, we take a closer look at the role of estoppel in a recent decision of Reed v National Contracting Services Pty Ltd [2025] NSWPIC 48 (‘Reed’) and its impact on decision making in proceedings.

The facts

The worker was employed by National Contracting Services Pty Ltd (‘NCS’) as a truck driver.  His duties involved transporting sand and gravel from a quarry to concrete plants.

On 22 June 2017, the worker was cleaning his truck when he slipped and fell, causing injury to his right ankle and consequential injuries to his lumbar spine and left knee.  Liability for the injuries was accepted.

The worker had a previous claim before the Personal Injury Commission (‘PIC’) in 2021.  His claim for payment of the cost L5/S1 anterior lumbar interbody fusion surgery was unsuccessful and an award was entered for NCS by Member Wynard in January 2022.

In February 2024, the worker’s treating specialist recommended the surgery once more and the worker made a further claim to that effect.  The claim for the proposed lumbar spine surgery was disputed in March 2024.  The worker commenced proceedings in the PIC costs associated with the proposed surgery.

There was also the issue of whether estoppel arose in relation to the L5/S1 anterior lumbar interbody fusion surgery.

The findings

Member Seaton found the question to be determined in the current proceedings was identical to the question before Member Wynard in the prior determination of 14 January 2022. 

Member Seaton found that whether a proposed surgery was reasonably necessary was a matter which was capable of change[1] with the passage of time.  In this case, the treating surgeon discussed worsening symptoms and the development of radiculopathy, associated with the worker’s lower back condition, which in the Member’s view was sufficient to warrant changes in circumstances. 

The Member found there was a new question about whether the surgery was reasonably necessary at the time of her decision with regard to the current circumstances.  Accordingly, she found no estoppel arose.

After considering the matter the Member found the surgery was reasonably necessary and made orders for the payment of the associated costs by NCS.  

Takeaways 

In workers compensation claims it is not uncommon for symptoms to change and worsen with the passage of time.  Based on this decision, the worsening of symptoms is sufficient to warrant a change in circumstances and thereby challenge the application of estoppel.

It is important to keep this in mind when considering claims and look at whether the circumstances have changed since any previous findings in the Commission.  If they have, then insurers should make sure to undertake the necessary investigations to be able to make a soundly based liability decision based on the worker’s current presentation.

Authors: Kate Ralph and Kate Nammour