Revisiting the Causation Equation – “Material Contribution” not “Solely Caused”

In Brief

• A Medical Assessor does not reverse the onus of proof when they disregard alternative findings due to lack of evidence after having made a positive finding.
• A Medical Assessor is not required to respond to arguments which are not lawfully made.
• When assessing causation, the question is whether a motor accident made a material contribution to the cause of an injury, not whether the motor accident was the sole cause of the injury.

Facts

The Supreme Court handed down its decision in Insurance Australia Limited t/as NRMA Insurance v Duc Thuong Le [2024] NSWSC 1022 on 19 August 2024.

The Claimant was a passenger in a motor vehicle in a high-speed collision. The Claimant had to extricate himself from the vehicle through a window with the help of a bystander. The Claimant then behaved erratically, standing in the middle of the road. A police officer pulled him off the road, but he started kicking and thrashing. When he was restrained on the ground, he started beating his head on the ground forcefully and repeatedly.

The Claimant was diagnosed with mild traumatic brain injury and various soft tissue injuries. Urine testing confirmed that he had consumed illicit drugs.

The Insurer disputed that the Claimant sustained above-threshold injuries. The key issue was whether any head or brain injury was caused by the accident as opposed to the Claimant’s own conduct following the accident.

The threshold injury dispute was assessed by a Medical Assessor and then referred to a Medical Review Panel.

The Review Panel found that the accident was more than a negligible cause of the Claimant’s head injury because the accident was a high-speed collision and the Claimant had to be extricated through a window. The Review Panel added that as there was no evidence to establish that the Claimant was agitated prior to the accident. His agitation and his act of striking his head on the ground was due to the accident in addition to the stimulant drugs he consumed.

The Insurer sought judicial review of the Medical Review Panel’s decision.

Supreme Court Reasons

Justice Price rejected all four grounds of review raised by the Insurer:

Ground 1

The Insurer submitted that the Review Panel reversed the onus of proof, impermissibly, when it found that there was no evidence that the Claimant was agitated before the accident.

Justice Price cited the reasoning of Hoeben CJ at CL in Allianz Australia Insurance Limited v Mackenzie & Ors [2014] NSWSC 67, that it is acceptable for a review panel to disregard alternative findings due to lack of evidence after having made a positive finding (at [38]-[39]).

Accordingly, Justice Price found the Review Panel’s mode of reasoning was acceptable as the panel had made an initial finding that there was a causal connection between the accident and the Claimant’s head injury before referring to the absence of evidence of agitation prior to the accident.

Ground 2

The Insurer alleged that there was internal inconsistency in the Review Panel’s reasoning process.

The Insurer noted that the Review Panel diagnosed the Claimant as having a brain injury based on his GCS and seizure (at [168]), found the seizure to be unrelated to the accident (at [176]), but then concluded that the brain injury was a result of the accident.

Justice Price noted that mention of “the seizure activity observed” at [168] referred to observations by an ambulance officer. Although the Review Panel considered that the accident did not contribute to the Claimant’s seizure, the Review Panel was still allowed to take the seizure activity observed by the ambulance officer into account as a factor in reaching the conclusion that, on the balance of probability, the Claimant sustained a mild traumatic brain injury as a result of the accident.

Ground 3

The Insurer alleged that there was no evidence to support that the Claimant sustained a head injury as a result of the accident.

Justice Price cited Naxakis v Western General Hospital (1999) 197 CLR 269 per McHugh J at [39] and Origin Energy LPG Ltd v Bestcare Foods Ltd [2013] NSWCA 90 per Ward JA at [88]-[90] and affirmed that the test is whether there was no evidence that ought reasonably to satisfy the decision maker that the fact sought to be proved is established.

Justice Price noted that the Review Panel’s finding was based on the following:

• The accident occurring at high speed.
• The Claimant had to extricate himself from the vehicle through a window with the help of a bystander.
• There was no evidence of the Claimant being agitated prior to the accident.
• The Claimant did, however, behave erratically post-accident before he began beating his head on the ground.

Justice Price concluded that there was sufficient evidence before the Review Panel to establish that the accident caused or made a material contribution to the Claimant’s head injury.

Ground 4

The Insurer raised in its submissions to the Review Panel that the Claimant’s head injury may have been caused by three possible mechanisms.

Specifically, the insurer identified the following three possibilities:

1. Whether the Claimant solely suffered a brain injury in the accident.
2. Whether the Claimant solely suffered a brain injury due the self-inflicted head strikes.
3. Whether there was a brain injury in the crash as well as self-inflicted head strikes.

The Insurer alleged the Review Panel erred because it failed determine which of the three possibilities was the cause.

Justice Price found that the Review Panel’s failure to specifically address the three possibilities raised by the Insurer did not amount to a failure to accord natural justice and/or jurisdictional error, for the following reasons:

• The scope of the Review Panel’s functions are found in s 7.26 of the Motor Accident Injuries Act 2017 subject to guidance provided by the Motor Accident Guidelines (MAGs).
• The Review Panel’s task was to determine whether the Claimant’s head injury was caused or materially contributed to by the accident.
• Clause 6.7 of the MAGs provides that the accident did not have to be sole cause of the injury. The accident merely had to be a “contributing cause, which was more than negligible“.
• The three possible scenarios advanced by the Insurer were matters of fact which the Review Panel was under no legal obligation to answer.
• The Review Panel did, however, directly address the Insurer’s substantive argument that that the Claimant’s head injury was not causally related to the accident but was, rather, self-inflicted.

As none of the grounds raised by the Insurer was accepted, the Insurer’s summons seeking judicial review was dismissed.

Key Learnings

Whilst the Insurer advanced four arguments in the Supreme Court, the key takeaway is that neither a Medical Assessor nor the Medical Review Panel is required to specifically address an argument which has no lawful basis.

In  Duc Thuong Le, the Insurer criticised the Review Panel for not addressing the three causation scenarios it had posed, two of which were whether the Claimant’s head injury was “solely” caused by the accident or “solely” caused by him subsequently striking his head against the ground.

The problem was that the questions that the Review Panel needed to address were determined by the statutory provisions, not the parties’ submissions.

Whether an event was the sole cause of the Claimant’s head injury was not a question which the Review Panel was lawfully required to consider.

Rather, clause 6.7 of the MAGs only required the Review Panel to address whether the motor accident made a material contribution, which was more than negligible, to the cause of the Claimant’s head injury.

Given that the Review Panel had addressed the causation question it was required to address by the MAGs, there was no denial of natural justice or any failure of jurisdiction.