We write to advise that we have determined to reject your claim for compensation because we are not satisfied on the balance of probabilities that you suffered any peripheral neuropathy in consequence of any injury by you arising from your employment with the Council. Further, we consider it likely that any development of peripheral neuropathy and the use of nitrous oxide predates that asserted injury and/or is due to other drug or alcohol abuse which existed and predated any work injury and we consider your use of nitrous oxide and or other drugs constitutes a

breach of your obligation of mutuality and we have therefore determined to reject your claim.

1. In his submitted affidavit, the applicant deposed the primary injury was such that:

I drove to the Council Chambers. I remember it was still early in the morning, sometime around 9am. There were around 8 bags of rubbish located next to a shipping container outside of the building. Some of the bags were large plastic black bags and some were large hessian sacks.

The bags weighed around 5kg each, however the hessian bags were heavier. The hessian bags weren't tied up.

I loaded the bags into the back of the ute and drove to the dump which was a few kilometres away. The dump was unmanned so I drove in, unlocked the gate and pulled up my ute next to the area where soft rubbish was disposed of. I stepped outside the ute and stood next to the back passenger side. I leaned over to grab the bags two at a time. I was holding the bags horizontally and I carried the top and bottom of the bag using each hand. I was throwing the bags into rubbish area. I leaned over to grab the last two hessian bags, picked them up and I felt something sharp on the outside of my hand on the index and middle finger. It felt like I had been bitten by something. My right hand instinctively dropped the bag. I caught the weight of the bag with my left side and then felt a sharp pain across my low back. I heard a popping type noise. I wasn't able to continue what I was doing because of the pain. I inspected my right hand and saw a small cut across the middle and index finger towards the bottom of my finger. I didn't see what cut my fingers, but I assumed it was something sharp like wire or glass. There was only a small amount of blood.

The pain in my back was severe. I would rate the pain as a 10 out of 10. The pain was unlike anything I had ever experienced before.

I took a few moments to collect myself, however I couldn't finish the job. I couldn't pick up the bags with the way my back was feeling. I got back in the ute. The back pain was not easing up so I made the decision to drive home which was around 7 or 8 km away and it was close to my smoko break. My girlfriend was home at the time. I told her what happened and that I hurt my back at work. I had some Panadol and ibuprofen and then laid down for a moment.

...

I sent an SMS to Brian [Lamont] on the following day (8 August 2023) letting him know what I wouldn't be in for the day. I mostly stayed in bed

for the next few days. I already had pain medication in the house so I was able to take that. I took more than usual to help cope with the pain. The side effect of excessive Tramadol is that I can feel very drowsy.

1. I take reference to the Tramadol that the applicant had in his house to be from earlier prescriptions following attendances at the Coober Pedy Clinic.

1. The records of the Clinic indicate that on 1 June 2023, the applicant saw Dr Wilks via telehealth, who noted that the reason for the consultation was due to sleeping issues, but also due to the applicant's "back playing up after physical work" for which he prescribed tramadol.

1. The applicant contends the entry is wrong: that his complaint was not of back pain, but side pain from using a whipper snipper. The applicant explained in his affidavit that:

When allocated to whipper snipper duties, I would strap the whipper snipper onto a harness to help absorb the weight. Over time, I noticed a niggling feeling on the right side of my upper body, just below my armpit. I am right-handed so the whipper snipper would sit on the right side of my body. There were some weeks that I might use the whipper snipper for nearly all of the day and three times per week. It would be worse at the end of the day when I finished work, but it never got so bad that I felt I couldn't continue. I felt like a strain on my side and the Tramadol would help ease the pain. It was helpful that once a month we would do the meter checks which would take the full week to give me a break from the whipper snipper duties. I did not report the pain from whipper snipper to the Council. I don 't have a whipper snipper at home as my rental property didn't have a garden to maintain. I didn't do any whipper snipper duties outside of work while in Cooper Pedy.

I wanted to see a GP about the strain type feeling so I arranged an appointment at Coober Pedy Medical Clinic which was booked for 10 August 2023. The appointment had been booked a week or two prior to the actual appointment.

On this issue, for his part in his evidence, Dr Wilks confirmed that the only history provided to him was as appeared in the notes: that the applicant's back was playing up after physical work.1 Later in his evidence, Dr Wilks surmised from subsequent discussions and events that the "physical work" to which he was referring, was from use of the whipper snipper.2 At no point was it suggested to Dr Wilks that the reference to "back" in his notes and his evidence, in fact related to symptoms in the side or flank.

1 Transcript 13/3/25 at 172.20-.23; 196.17-.19; 197.7-.12.

2 Transcript 201.29-203.16.

1. On 4 July 2023, the applicant re-attended the Clinic complaining of chronic pain and seeking a repeat script for tramadol, which was provided along with a warning as to the risk of addiction.

1. The applicant then attended the Clinic on 4 August 2023 for a further script for tramadol, which was provided. No note was made as to the reason.

I was able to consult with a doctor at the Coober Pedy Clinic on 10 August 2023. I was driven to the appointment by my girlfriend Nicole. Because Coober Pedy is a regional town, it is usually only locums available, other than a handful of doctors that will do a two week rotation.

With reference to the Coober Pedy Clinic records, I consulted with Dr McMullen. I am unable to recall this doctor and I believe I only saw him on this occasion. I felt impacted by the Tramadol during this appointment. The appointment had been booked prior to discuss the whipper snipper usage and the niggling feeling on my right side. I didn't know if I was meant to be reporting the work incident in detail to the GP because I had assumed that Brian would get back to me about what I needed to do. I remember vaguely mentioning my low back but I don 't think I went into specifics. I assume the reference to ' pain free ' is in relation to being pain free on my right side of my body. I was taking a lot of pain medication which would have dulled the right side pain, however I could still feel low back pain. I was given a medical certificate from 7 August 2023 to 10 August 2023. I remember the appointment being very brief and I am confident that Dr McMullen did not examine my lower back. It was less than 10 minutes. At the time of the appointment, I was unaware that a Work Capacity Certificate was required for a work injury as I have never had a workers compensation claim before this. I recall that Dr McMullen did not take any notes during the consultation.

1. The applicant's then partner, Nicole, attended the medical appointment on 10 August 2023 with him. In her affidavit, she stated:

I drove Richard to his GP appointment on 10 August 2023. I was aware that this appointment had already been booked before his work injury. Over the past few weeks, Richard had been complaining to me about the whipper snipper causing him pain on his side. It would happen only when he had to perform whipper snipper duties for an extended period of time. I remember he would stop complaining for a bit but then I would hear about it again. He would take more pain medication to cope but it was never bad enough that he had to stop work.

It was either before going into the appointment or in consultation room, Richard and I had a conversation where he said he wasn't sure how to go

about dealing with his work injury and that he was waiting to speak to his boss first. I sat in with Richard and the doctor during the appointment. I remember Richard saying that his side would hurt when using the whipper snipper. I can 't remember whether it was the left or right side. I also remember Richard briefly mentioning that his low back was hurting but that was only in passing. The appointment was very brief, around 10-15 minutes.

LBP while whipper-snipping Has taken time off

Pain free now Requests med cert.

This is to certify that Mr Richard Adrian Schlie has received medical treatment and for the period of:

From: Monday, 7 August 2023

To: Thursday, 10 August 2023 inclusive,

And will be unfit to continue their usual occupation.

1. There is no reference in either of the affidavits, or the doctor's notes, to further scripts being sought or issued.

1. In a medical report dated 2 May 2024, Dr Wilks reports:

Richard tells me that he told Dr McCullen on 10/8/23 that using the whipper snipper aggravated the back pain caused by unloading the ute. Dr McCullen recorded and reported that using the whipper snipper was the cause of the pain. Dr McCullen's clinical notes are brief and do not give details of the conversation and I note that the time recorded for the consultation was less than six minutes, although it is possible that the file was not open for the whole of the time Richard and Dr McCullen interacted.

1. It appears that discussion between the applicant and Dr Wilks was in a consultation on 29 April 2024 where Dr Wilks records:

[H]as one certificate saying injury was due to whipper snipper raising suspicion of variable honesty. Other Dr's [sic] say the same (unloading ute). Richard says he told the doctor using the whipper snipper aggravates the pain and I think this has led to the error in report.

On 10 August 2023, I sent an SMS to Brian that my back was starting to feel better and I would be in on Monday.

The applicant's next medical appointment was on 15 August 2023 with Dr Ugwu. Dr Ugwu's notes of the consultation state:

Surgery Consultation

Injured his back 8 days ago while at work. He was trying to lift a heavy bag when something sharp cut his right hand. He tried to hold onto the object with his left hand and developed sudden back pain.

On medical leave since

Brought a form from work to fill in for his treatment plan He still has back pain, non radicular

No incontinence

or lower limb weakness

He has been using ibuprofen daily since incident

BP 111/76, pulse 85

Mild tenderness paraspinal muscles

Extension of lumber spine impaired to just about 10 degrees Normal TPR all limbs

form filled referred to physio

advised that opioids will not help his back pain trial of celebrex

review prn

Prescription added: CELEBREX CAPSULE 100mg 1 b.d.

1. This is the only entry recording the results of a physical examination since the first complaints were made on 1 June 2023 (which was a telehealth consultation).

1. The applicant was then reviewed by Dr Wilks via telehealth on 18 August 2023. His notes indicate "Is moving about. 20 tramadol lasted two weeks." A further script for tramadol was issued.
2. On 1 September 2023, the applicant consulted a physiotherapist, Mr Lum. In his report he noted examinations findings as:

Mobility - (I) nil aids L/Sp Active movements

Flex - reports tightness in low back area but no intense pain Ext - pain in centre of back

Lat flex - tightness R and L but no pain in low back Rotation - tightness with end range. R = L

Combined flex/rot R = L no real discomfort just tightness Combined Ext/rot R = L discomfort in centre of back

Palpation: tender over Erectors over L1-L5. Tender on PAIVM over L3/4, L4/5. Tender glutes and QL bilaterally

1. On 5 September 2023, the applicant consulted Dr Sorensen via telehealth, requesting a further script for tramadol until he sees Dr Wilks on 15 September 2023. A script was issued, but with the dosage increased from 1 capsule, twice a day as needed, to 1-2 capsules, three times a day as needed. No explanation for the increased dosage was recorded.

1. On 11 September 2023, the applicant consulted Dr Ugwu whose notes record:

Surgery Consultation

Seen last week here in practice- needs a medical certificate for those days Complaining of numbness on the soles of his feet for 5 days, no clear history of trauma on his feet

Previous history of back pain after trying to lift something

1. A lumber CT scan was arranged, and a further tramadol script was issued for the higher dosage.

1. On 15 September 2023 the applicant saw Dr Wilks in the surgery rather than via telehealth. Dr Wilks records "exacerbation of pain, including sternal pain. Tender to pressure there. Had yesterday and today off." A further script for tramadol at the higher dosage was issued. The applicant was yet to have his CT scan.

1. The applicant again saw Dr Wilks in the surgery on 21 September 2023, having had the CT scan in Pt Augusta. Dr Wilks' notes record:

Review CT.

Minor changes though mid lumbar with more significant degenerative changes of L5-S1

Still sore from drive to Pt Augusta.

Certificate of Capacity issued for time off for this week and previous light duties for the rest of the certificate

has had physic. Shown some exercises

1. A further tramadol script at the higher dosages was issued.

1. The applicant was next seen at the Coober Pedy Clinic on 28 September 2023 by Dr Adeyelu, who made comprehensive notes as follows:

Patient reported he injured his back at work on the [blank]

Patient also reported he been using more of the Tramadol than usual says not working as well and he is having a lot of side effects

he says he has ongoing constipation

He would like to stop the tramadol and move to endone

wants a script for 10mg endone which he will cut down to stop I asked why not taper th [sic]

tingling, going to the foot on and off has been going on for a while now

also reported numbness in the sole of both feet constant

has been on for 3 weeks or so now

it started with the right foot and a few days later, it went to the left foot and both have remained

the same since then no limb weakness

no saddle numbness, no incontinence, no limb weakness

pain in the lower back has improved noticeably with the exercises the physio showed him

No polyuria or polydipsia....

Alert, well oriented not pale or jaundiced exam of the LL

Power in the hips, knees, ankles - flex and ext are 5/5 sensation in the LL and the soles are normal

Pedal pulses are easily palpable

1. On the same day, the applicant consulted Dr Wilks at the hospital who records:

Came to ED. ?Directed by clinic. Request for Endone declined by Bayo.

Says wants just one box of 10mg which he will halve and will last 40 days.

Back is improving with physio, albeit slightly.

I told him if I had a dollar for every time someone said "just one box .... "

Previously had endone for partial amputation of finger and stopped after one box and has been able to quit

illicit opioids ?recently.

Also c/o side effects with tramal including constipation and anorgasmia. PLAN

Discuss pain mechanisms

Can have targin to avoid constipation. Can combine this with paracetamol.

1. The next consultation recorded was a telehealth consultation with Dr Ugwu on 6 October 2023, recorded by Dr Ugwu as follows:

Having problems with targin - giving him stomach upset requesting tramadol for his pain

Needs previous work certificate changed to work cover and a work cover form for this week.

1. Dr Ugwu prescribed tramadol at a dosage of 1-2 capsules, twice a day as required.

1. The applicant next saw Dr Muthu at the Clinic on 13 October 2023. Dr Muthu records:

1. Requested SA Workers Compensation medical certificate for Tuesday 10/10/2023 - unable to do any of his 6 hours of work Thursday 12/10/2023 - went back for 3 hours

due to recurrence of pain in low back with usual duties at current work. no further strain

duties include bending down to pick up litter with instrument has not been carrying anything heavy.

has been following exercises prescribed by physio no alarm symptoms. no incontinence

however does complains of tingling and numbness in hands and in both feet

has been going on for 6 weeks

no saddle numbness, no incontinence

1. Requested repeat script for Tramadol. says when in pain takes up to 2 per day.

Targin made his stomach upset. Tramadol no side effects

appears comfortable gait normal

FF 40 deg , BE 5 deg, LE 5 deg bilat normal tone power reflexed bilat normal KJ bilat

normal sensation bilat legs no paraspinal tenderness abdominal obesity noted

explained to patient - level of pain does not seem consistent with level of injury.

also subjective feelings of 'tingling' in hands difficult to explain given medical cert

advised to continue with physio prescribed exercises weight loss

core strengthening exercises further history:

says had unsafe levels of alcohol a few years ago when son had an MVA and became hemiplegic.

had been on sertraline since denies any THC or other drug use

1. Dr Muthu prescribed tramadol, 1-2 capsules twice a day as required.

1. On 27 October 2023, the applicant saw Dr Wilks complaining of back pain "12 out of 10". Tramadol was again prescribed with a trial of Lyrica (pregabalin).

1. On 31 October 2023, the applicant had a telehealth appointment with the Clinic, complaining of chronic pain, and was again prescribed tramadol.

1. The applicant then had a further telehealth appointment with the Clinic on 3 November 2023, complaining of "back pain - acute on chronic" and seeking a further tramadol script. It was provided, but the applicant was warned it could not continue. The applicant also reported he had not been taking the pregabalin with which he had been prescribed.

1. Thereafter, the applicant came under the care of specialists and the hospital, for treatment of his neuropathy.
2. In January 2024, the applicant was independently assessed by Dr Suyapto at the request of his solicitors, and Dr Panayiaris at the request of the respondent.

1. In his report dated 9 January 2024, Dr Suyapto recorded that the applicant complained of an ache in his back with no radiating pain to his leg. On examination, the most significant findings were of reduced thoraco-lumbar spinal movements and of tenderness over both L5/S1 facet joints. The diagnosis was of lumbar spine facet arthropathy as a consequence of the rubbish bag incident on 7 August 2023. Dr Suyapto considered the applicant should avoid bending, twisting or prolonged static posture and heavy lifting as a consequence.

1. In relation to the peripheral neuropathy, the applicant puts his case in the following way:

The worker is in pain from his back. He has an addictive personality. The painkillers are not working. He's got used to them. Dr White, for the employer, explains that. So the worker doesn't want to get back on the drink. He's beaten that. So in a setting where he can't get adequate, on his say-so, painkillers, he reverts to something he tried years ago, nitrous oxide. So those little cylinders that you put in a whipped cream 15 canister, laughing gas, nitrous dioxide, and he uses them. Your Honour will see, and we've got-the notes make it plain when the GP declines to provide further painkillers at an industrial level as the worker is asking for, so he self-medicates. He self-medicates with something he thought was legal, but he gets carried away with the quantity and ends up consuming over 1,000 of those little cylinders. That has a side effect. It blocks absorption of vitamin B, and as a consequence of that self-medication, he gets peripheral neuropathy, which is identified and treated in Adelaide under Professor Thompson when he starts losing the capacity to walk properly and the sensation in his hands.

The evidence

1. The applicant's evidence was that he commenced to inhale nitrous oxide over the weekend of 12-13 August 2023. The circumstances were set out in his affidavit as follows:

When I was struggling with the pain and I was running low on my pain medication that I started using nitrous oxide canisters to help cope. I had been taking more tablets than my prescription to deal with the pain from my low back. I recall that I was waiting for another appointment but I didn't have enough tablets to last me until the next consult. I was barely

able to get up and move so I either ordered nitrous oxide online or purchased them from the IGA in town. It was meant to be a temporary measure only and while I was waiting for another prescription to help with the back pain.

Nitrous oxide canisters are small silver pressurised metal canisters which are used to whip cream. When inhaled, the cannisters given an instant high and pain relief sensation. It was something I had done when I was around 19 or 20 years old when socialising with friends, however I had given up this habit as an adult. I had not used a nitrous oxide canister in many years, however I thought that the feeling would help alleviate the pain from my lower back. When I would inhale the nitrous oxide canister, the feeling would not last long. I would insert a canister into a whipped cream dispenser and screw back on the lid and press down on the handle so the gas could be inhaled. I would feel an immediate high for around 30-60 seconds. I would feel good and happy and able to manage the pain. Because it would be such short relief, I found myself rapidly going through them and constantly loading canisters, loading two or three at a time. I started to become addicted to them and crave the high feeling from them because of the pain relief.

1. The unchallenged medical evidence of Professor Campbell Thompson is that the applicant went on to develop a vitamin B12 deficiency causing peripheral neuropathy which has arisen due to nitrous oxide usage.

1. The evidence of the applicant was that the peripheral neuropathy initially manifested itself as numbness in the sole of the left foot, progressing to both feet, then tingling and numbness in both feet, then the same tingling and numbness in both hands as well. By October 2023, it "had become so bad that there were some days I was struggling to walk or hold onto things with my hands."

1. Eventually, the applicant was flown to Adelaide and admitted to the RAH on 10 November 2023, by which time:

my symptoms were so severe I could barely walk. I had to lift up my feet when walking. I couldn't feel anything with my hands and could barely pick anything up. It felt like constant electric shock sensations or needles stabbing me in my hands and feet.

1. There, the diagnosis was made and a connection was drawn with the nitrous oxide use. The applicant's evidence was that he immediately ceased nitrous oxide use and has not returned to it. He was prescribed vitamin B.

1. By March 2024, the symptoms had improved such that he only had slight numbness in his hands but his feet remained unchanged.

1. At the time of swearing his affidavit in August 2024, the applicant says:

I felt like the numbness and tingling were finally improving, however in the last few months, I have noticed the symptoms getting worse. Now it feels like a big blister over the pads of my toes and numbness in my heels. There is numbness in between my fingers where they connect to my hands, however I am still able to grip items.

1. In his evidence at trial, the applicant deposed that his hands were "fine", but he still couldn't feel the soles of his feet. That situation with his feet had remained unchanged for about a year. As a consequence, he has to be careful when walking on rough or stony ground, or on stairs or slopes.

1. The thrust of the respondent's case was that the applicant simply was not a credible witness and that his evidence should not be accepted. I will address this in more detail later in my consideration of the evidence.

1. There was really no contest on the medical evidence.

1. As mentioned previously, the opinion of Professor Thompson that the peripheral neuropathy was as a result of the nitrous oxide was unchallenged.

1. As to the evidence of Dr Suyapto, Dr Panayiaris essentially agreed.
2. Although put in issue in its Statement of Issues and Contentions, the respondent did not dispute that the applicant suffered some injury on 7 August 2023.
3. Rather, the respondent submitted any such injury was minor and quickly resolved.
4. However, it was not put to Dr Suyapto, nor was it the evidence of Dr Panayiaris, that any injury sustained on 7 August 2023 was not the cause of the facet arthropathy diagnosed.

1. I accept that the applicant suffered an injury to his low back on 7 August 2023 in the incident described by him. It is not seriously

challenged by the respondent and is overwhelmingly supported by the evidence.

1. However, for the reasons that follow, I do not accept his evidence as to the severity of the symptoms resulting from it.

1. Firstly, the events of 10 August 2023. I do not find the account of the applicant and his partner of the consultation with Dr McMullen to be credible. On his history, the applicant has never been reluctant to seek pain relieving medication. If the pain he complained of following 7 August 2023 was as extreme as he has said, I cannot accept that he would not seek pain medication from Dr McMullen, nor report that he was largely pain free. To suggest that reporting was regarding the side, but that he was suffering serious low back pain which he did not mention because of uncertainty over the issue of worker's compensation, I do not accept.

1. This is reinforced by his text to work which immediately followed that consultation. The text appears to indicate that at most he had some minor ongoing low back symptoms which he expected quickly to resolve. That does not suggest that he would not require further strong pain medication.

1. The subsequent discussion with Dr Wilks regarding that consultation, and the report of Dr Wilks that followed, simply muddies the water further and gives an even more implausible explanation, given that any issues with using a whipper snipper pre-dated the 7 August lifting incident.

1. None of the medical examinations that followed over the ensuing months revealed any major clinical findings to suggest a significant low back injury. On 15 August 2023, the most significant finding was of mild tenderness of the paraspinal muscles. The examination findings of the physiotherapist on 1 September 2023 are generally of tightness rather than discomfort or pain. On 15 September 2023, the note was simply that he was tender to pressure on the sternal (chest) area. On 28 September 2023, he reported that his back pain had improved noticeably with exercise.

1. However, in light of the unchallenged medical evidence of Drs Suyapto and Panayiaris, I find that the low back injury has persisted and that the diagnosed facet arthropathy has resulted from it. Moreover, I find that condition was, and continues to be, partially incapacitating for work.

1. In relation to the peripheral neuropathy, to be compensable I must firstly find that the ingestion of the nitrous oxide was in an attempt to provide relief from the pain of the primary injury. I do not so find this to be.

1. Given the finding at [63] and following above, there is nothing to support the assertion of the applicant that he had exhausted his pain medication by the weekend (2 days later) and was unable to source any more, such that he turned to nitrous oxide for relief. On 15 August 2023, he did not tell Dr Ugwu that he had used up the tramadol - rather, that he simply managed the pain with ibuprofen. On 18 August 2023, he told Dr Wilks that the tramadol had lasted 2 weeks, which would equate with no more than using the prescribed dosage.

1. Further, in light of my finding that there was no significant injury, I do not find it caused the applicant significant pain. Rather, the level of consumption of nitrous oxide was more an indication of addiction, which on his history cannot be said (and which addiction is not claimed) to follow from the back injury on 7 August 2023.

1. Moreover, the nitrous oxide use continued even after the applicant was sourcing significantly increased dosages of tramadol through the Clinic, such that there was no pain reason for its continuing use.

1. In any event, I find that the claim for a compensable peripheral neuropathy is precluded by s 8(2)(b)(ii) of the Return to Work Act 2014 (the Act).

(2) However, a worker will not be entitled to receive any services or benefits under this Act in relation to an injury if -

(a) the worker is guilty of misconduct or acts in contravention of instructions from the employer during the course of an attendance under section 7(5); or

(b) it is established on the balance of probabilities that the injury is wholly or predominantly attributable to -

(i) serious and wilful misconduct on the part of the worker; or

(ii) the influence of alcohol or a drug voluntarily consumed by the worker (other than a drug lawfully obtained and consumed in a reasonable quantity by the worker).

(3) Subsection (2)(a) does not apply in a case of death or permanent total incapacity for work and subsection (2)(b) does not apply in the case of death or serious and permanent injury.

1. I consider the nitrous oxide is a "drug" within the meaning of ss (2)(b)(ii). "Drug" is defined as "a chemical substance taken for non-medical reasons to bring about a change in behaviour, mood or perception, as a narcotic, hallucinogen etc."3

1. I do not consider that ss (3) applies as I do not find the permanent effect of the peripheral neuropathy is "serious." "Serious" is an imprecise word capable of many definitions and applications - even within the Act: "serious and wilful misconduct"; "seriously injured worker". In this setting, I consider the juxtaposition to "death" suggests a meaning at the more extreme end of the spectrum of applications - for example, quadriplegia or paraplegia.

1. In the case of the applicant, the long-term effects to which he deposes is a loss of sensation on the soles of his feet, requiring him to take care on certain surfaces. I do not consider that fulfills the definition. In so saying, I note the views of Dr Panayiaris suggesting the contrary. It is for me to determine the meaning. His consideration did not have regard to context.

1. I find that each of the facet arthropathy and the peripheral neuropathy can be said to be productive of a degree of partial incapacity.

1. The facet arthropathy places functional limitations on the movement of the back.

1. The peripheral neuropathy imposes a restriction on mobility, especially over uneven surfaces. However I cannot say that, absent the facet arthropathy, the applicant would have required modification to his usual duties to accommodate it. Rather, it would simply have required him to take more care.

1. I invited further submissions from the parties in writing to address the consequences of such a potential finding.

1. The written submissions offered limited assistance on the question of incapacity and focussed more on the issue of mutuality.

1. The seminal decision on the issue of concurrent compensable and non-compensable incapacities is Hartwell v Electricity Trust of South Australia4 where King CJ observed:

Apart from the effects of the compensable injury, the appellant was rendered incapable of doing work of any kind by reason of causes unrelated to his injury. In those circumstances s.67 can have no application. More difficult problems may arise when a worker is disabled by a supervening non-compensable cause from performing some but not all work which his compensable injury would have permitted him to perform. The resolution of such problems would depend upon the circumstances of the case and may involve questions of degree. The governing principle of the Act is that the employer is liable for the results of the incapacity which is related to the employment, but not for incapacity which is so related. If a worker is unable to perform work which is available, not because of incapacity caused by the compensable injury, but because of incapacity caused by other factors, the section cannot operate to give rise to notional total incapacity. Whatever difficulties the application of the section might pose in other cases, I see no difficulty where, as here, the worker's ability to perform work which the injury would have permitted him to perform, is totally destroyed by other causes.5

1. However, s 67 of the Workers Compensation Act 1971 (WCA) to which King CJ referred was quite different from the present provision.

For the purposes of determining the amount of weekly payments provided for by section 51 of this Act, partial incapacity for work shall be treated as total incapacity for work except -

(a) during any period in respect of which the employer proves that work for which the workman was fit was made available to the workman by the employer; or

(b) during any period in respect of which the employer proves -

(i) that it was not reasonably practicable for the employer to make available to the workman work for which the workman was fit;

(ii) that such work was reasonably available to the workman elsewhere.

4 (1982) 29 SASR 365.

5 At 369.

1. The WCA was replaced in 1986 by the Workers Rehabilitation and Compensation Act 1986 (WRCA) under which the relevant provision was s 35(2), which provided:

(a) a partial incapacity for work over a particular period shall be treated as a total incapacity for work over that period unless the Corporation establishes that suitable employment for which the worker is fit is reasonably available to the worker in respect of that period...

1. In relation to both s 67 and s 35, King CJ noted:

It is settled law that the notion of unavailability to a worker of work for which he is fit connotes that he is ready and willing to perform such work.

...This is the principle of mutuality which is referred to in the Corporation's determination.

Those cases were decided upon statutory provisions which made the failure of the employer to provide suitable work the precondition or one of the preconditions of partial incapacity being treated as total. ...

...If the employer made suitable work available to the worker, the effect was to deprive the partial incapacity of the potential to be treated as total irrespective of whether the worker might be unable to avail himself of the work by reason of altered circumstances such as having moved from the locality. With such a provision mutuality required a readiness on behalf of the worker to avail himself of the work made available by the employer with which he was employed at the time of incurring the disability.

...The precondition under s 35(2) does not have an aspect which is specific to a particular employer. The precondition is the non-availability of suitable work generally. The mutuality required by s 35(2) is therefore

a readiness and willingness to perform work which is reasonably available and is not necessarily negated by the worker's unavailability for work provided by the employer in whose employment the disability occurred.6

1. In contrast, the present version is s 39 of the Act, which relevantly provides:

(1) Subject to this Act, if a worker, other than a seriously injured worker, suffers a work injury that results in incapacity for work, the worker is entitled to weekly payments in respect of that incapacity in accordance with the following principles:

(a) if any period of incapacity for work occurs within the period of 52 weeks from the date on which the incapacity for work first occurs (the first designated period) -

6 Workcover Corporation (Plas-Tec Pty Ltd) v Gregor [1994] SASC 4450; (1994) 62 SASR 283 at 285-286.

(i) for any period during the first designated period when the worker has no current work capacity - the worker is entitled to weekly payments equal to the worker's notional weekly earnings; and

(ii) for any period during the first designated period when the worker has a current work capacity - the worker is entitled to weekly payments equal to the difference between the worker's notional weekly earnings and the worker's designated weekly earnings;

(b) if any period of incapacity for work occurs within the period of 52 weeks beginning immediately after the end of the period that applies under paragraph (a) (the second designated period) -

(i) for any period during the second designated period when the worker has no current work capacity - the worker is entitled to weekly payments equal to 80% of the worker's notional weekly earnings; and

(ii) for any period during the second designated period when the worker has a current work capacity - the worker is entitled to weekly payments equal to 80% of the difference between the worker's notional weekly earnings and the worker's designated weekly earnings.

(2) For the purposes of this section, the designated weekly earnings of a worker will be taken to be the current weekly earnings of the worker in employment or self-employment (if any) but not so as to include a prescribed benefit.

1. What is immediately apparent is that whereas s 67 and s 35 had regard to amounts the worker was capable of earning from employment reasonably available, the present section only has regard to current weekly earnings. Thus, under s 67 and s 35, whilst incapacitated, weekly payments would be calculated as the difference between the level of pre-injury earnings and the earnings the worker is capable of earning in employment reasonably available (irrespective of whether the worker is actually earning that amount or not); under s 39 a worker would be entitled to the difference between their notional weekly earnings and the amount actually earned. This distinction was acknowledged by the Court of Appeal in Department for Child Protection v Morris.7

1. The safeguard to the compensating authority in the case of s 67 and s 35 was that deemed total incapacity was conditional upon the worker satisfying their obligations of mutuality.

7 [2022] SASCA 131 at [121].

1. With the removal under the present Act of the concept of earnings from work reasonably available, the question arises as to whether the principle of mutuality operates in the same way. If not, does Hartwell continue to apply?

1. The plurality of the Court of Appeal had occasion to consider the interpretation of the present mutuality provisions in contrast with the earlier enactments in Department for Child Protection v Morris. In Morris, the Court quoted with approval the explanation of Gilchrist DPJ that:

It can be seen that the situation under the current Act is quite different. If a worker breaches mutuality under the current Act because he or she has refused to take up an offer of suitable duties, this would entitle a compensating authority to discontinue the worker's weekly payments under s 48. If the worker could then submit a claim for weekly payments and not remedy the breach, the discontinuance would be rendered ineffective because under the current Act, 'designated earnings' do not include what the worker could earn from suitable employment.

This is such an unlikely outcome, I do not consider that this is what Parliament intended. I think that what Parliament intended, was that unlike the analogous provision in the repealed Act, which facilitated the resetting of weekly payments, the relevant provision in the current Act serves a different purpose. I think that what it is intended to achieve is to simply enable the discontinuance of weekly payments and that once the discontinuance has occurred, the entitlement will only recommence once mutuality has been restored.8

1. The Court of Appeal in Morris made it clear that the breach of mutuality provisions under the Act are more expansive than under the earlier enactments; not less so. The provisions apply to a worker who is totally incapacitated, not merely partially so:

To return to an earlier example by way of illustration, insofar as the respondent points to situations where a totally incapacitated worker is beset by a heart attack which, independently of any work injury, totally incapacitates the worker, Hartwell and the cases which have followed it demonstrate that circumstances such as these are clearly recognised as a breach of the obligation of mutuality which will now furnish a basis for discontinuance. That operation and effect of the legislation is not penal but concerned with ensuring that only those workers who are only incapacitated by work-related injuries, rather than non-work-related injuries, continue to receive weekly payments.9

8 Morris v Department for Child Protection (No 2) [2020] SAET 148 at [32]- [33].

9 Note 7 at [165].

...under the current Act, the operation of the concept of mutuality is no longer tethered in any way to a deeming provision. It operates solely in the extended and different context of providing a basis for ceasing weekly payments, and does so in circumstances where there no longer appears to be any basis for suggesting that the worker might retain an entitlement to claim lesser weekly payments based upon his partial incapacity prior to the supervening total incapacity by reason of the breach of his obligation of mutuality. The resumption of payments would require a restoration of mutuality.10

1. From this, I distil the principles that if a worker has a partial incapacity from a compensable injury and an incapacity from a non-compensable injury, an entitlement to weekly payments may be dependent in the first instance on the nature and extent of the individual incapacities. If the compensable incapacity is the same as, or subsumed by, the non-compensable incapacity, there is no entitlement to weekly payments. However, any entitlement that may exist may cease if there is a breach of the obligation of mutuality and may only be restored if and when the breach is remedied. The burden of establishing a basis for a discontinuance is on the respondent. The burden of establishing any ongoing or fresh entitlement thereafter rests upon the applicant.11

1. The medical evidence before me does not readily distinguish between the incapacity flowing from the facet arthropathy from that flowing from the peripheral neuropathy. While the differences in functionality are readily apparent, how that translates into work capacity is less clear cut.

1. On the limited evidence before me, I cannot find that suitable employment to accommodate the back complaint - avoiding bending, twisting or prolonged static posture and heavy lifting - would require further modification to accommodate the peripheral neuropathy. However, on the applicant's own evidence there was a period at least leading up to and including his hospitalisation in RAH in later 2023 when the peripheral neuropathy was significantly incapacitating. I would need to hear further submissions from the parties as to the period involved, as it would seem probable that the applicant would have no entitlement to weekly payments during any such period.

1. On the issue of mutuality, it is raised by the respondent in its Statement of Issues and Contentions as to "whether the use of nitrous oxide gas constitutes a breach of mutuality"12 and supported by the contention that

10 Note 7 at [188].

11 Seal v Transfield Services (Australia) Pty Ltd (2010) 108 SASR 312, [178]-[179] (Kourakis J).

12 RSIC 2.3.

"the use of the drug at the level consumed by the worker constitutes a breach of the obligation of mutuality."13

1. To the extent that the respondent expands its allegations in its final submissions to include alcohol and marijuana use and misuse of prescription medication, I decline to have regard to them as not being properly before me.

1. Although not clearly articulated by the respondent, the nature of the breach of mutuality alleged appears to be an assertion that the nitrous oxide use adversely impacted on the applicant's capacity to undertake otherwise suitable duties, either by virtue of the immediate effects of its use, or by virtue of the consequential peripheral neuropathy.

1. I have already dealt with the issue of incapacity flowing from the peripheral neuropathy.

1. In relation to the short term effects of nitrous oxide consumption, the only real evidence I have is from the applicant, to indicate the effects only last a few seconds, and that he did not use it while working. From this, I cannot conclude that its use away from work adversely impacted his capacity to work.

1. Accordingly, no breach of mutuality as properly raised by the respondent is made out.

1. The applicant suffered a facet arthropathy as a consequence of a low back injury sustained on 7 August 2023 and has been partially incapacitated thereafter.

1. The applicant suffers a peripheral neuropathy which did not arise in compensable circumstances and which for a time was significantly incapacitating but is no longer so.

1. There has been no breach of mutuality as alleged.