Causation: ‘common sense’ or ‘but for’ test?

In the matter of C Reagh Pty Ltd v Gaydon [2020] NSWWCCPD 63 (20 October 2020) Deputy President Michael Snell of the Workers Compensation Commission (‘WCC’) was required to consider whether the Arbitrator correctly applied the causation test established in Kooragang Cement Pty Ltd v Bates (1994) (‘Kooragang’) – being a ‘common sense evaluation of the causal chain’.


Ms Deanna Moodley (‘the deceased’) was employed as a cook by the appellant, C. Reagh Pty Ltd, when she suffered an injury to her back whilst lifting 20kg drums of cooking oil. The injury was the subject of WCC proceedings, which progressed to a contested arbitration hearing on 7 November 2012.

Following the hearing, the deceased boarded a delayed flight back to Dubbo from Sydney. After boarding she complained of sweating, nausea and shallow breathing; and later became unresponsive. Attempts to revive her were unsuccessful. An autopsy revealed she had unfortunately suffered a heart attack.

The deceased’s de facto partner, Mr John Gaydon (first respondent), made a claim for death benefits pursuant to section 25 of the Workers Compensation Act 1987 (NSW) on the basis there was a causal link between the ‘stressful’ arbitration hearing and the death. The insurer disputed the death resulted from the accepted back injury. Proceedings were commenced in the WCC joining the deceased’s dependent children as the second and third respondents, and the matter was heard by Arbitrator Burge. 

Arbitrator’s decision

The claimants relied on expert medical evidence linking the deceased’s death to the cross-examination at the hearing, the provision of evidence by the deceased’s co-worker challenging her claim, and the stress of the delayed flight.

Arbitrator Burge concluded that, when applying the ‘common sense’ causation test described in Kooragang, the stress of the arbitration hearing was the cause of the deceased’s death. He framed his reasoning as follows:

Were it not for her original injury, the [deceased] would not have been at the hearing…I am of the view the deceased suffered her fatal myocardial infarction as a result of the stress occasioned by the hearing.


The decision of Arbitrator Burge was appealed on three grounds:

  1. Error in fact and law in failing to properly evaluate whether the stress of the arbitration hearing was causative of a heart attack;

  2. Error in law in applying the wrong causation test to determine the heart attack resulted from the back injury; and

  3. Error in fact and law in finding the death resulted from the accepted back injury.

Ground 1 failed. The appellant made submissions on matters not raised at the arbitration hearing, and accordingly could not rely on these arguments on appeal.

With respect to grounds 2 and 3, the appellant submitted that Arbitrator Burge had:

  • Incorrectly applied a ‘but for’ causation test despite alluding to the need for a ‘common sense causal link’ to exist between the injury and the death; and

  • In considering the causal link, he incorrectly drew an analogy between the circumstances of the deceased’s death and a case involving a worker who suffered a further injury whilst attending a medical appointment in connection with the earlier injury (in which case, the further injury was compensable).

Further, it was submitted establishing the causal connection was dependant on whether the back injury and any physical limitations had resulted in the heart attack. The appellant argued there was no feature of the deceased’s compensable injury or its consequences that contributed to the hearing or the heart attack. 

The claimants argued the deceased’s attendance at the hearing was a critical factor in the chain of causation. Although they accepted the Arbitrator had applied a ‘but for’ test, they submitted he in effect applied a common sense evaluation of the evidence which ultimately led to his conclusion.


Deputy President Snell held Arbitrator Burge incorrectly relied upon a ‘but for’ test. It was clear the Arbitrator’s findings were dependent on the proposition that but for the injury on 5 March 2012, the deceased would not have been at the hearing or subject to cross-examination.

Deputy President Snell criticised the analogy used by Arbitrator Burge, observing there are many incidents which could occur at a medical appointment which would not have a sufficient connection to the injury.

The employer’s appeal was upheld and the dispute was remitted for re-determination.

Deputy President Snell concluded by observing the main issue between the parties was essentially the ‘scope of the matters that should be considered in properly constituting the chain of causation’. He referred to Kooragang and emphasised that matters beyond a medical nature may be relevant to considering the chain of causation. He observed a potentially relevant matter which had not been previously raised is whether the outcome of the original proceedings was a relevant factor in the chain of causation.


The decision highlights the fine line between the application of the ‘common sense evaluation of the causal chain’ and ‘but for’ causation tests. The decision confirms the Kooragang test is to be applied when considering whether there has been a break in the chain of causation between the original injury and a consequential condition/injury. 

Given the concluding remarks of Deputy President Snell, it will be interesting to see whether the nature of the original proceedings and/or its outcome are considered to be relevant factors in the chain of causation between the back injury and the deceased’s death – from a ‘common sense’ perspective. Stay tuned for the next instalment in this interesting case.

Author: Durga Shivaji

Contributing partner: Mick Franco