EAST METROPOLITAN HEALTH SERVICE -v- ELLIS (by his next friend CHRISTOPHER GRAHAM ELLIS) [2020] WASCA 147 (10 September 2020) - WASCA 2020 case summary — Zoe

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EAST METROPOLITAN HEALTH SERVICE -v- ELLIS (by his next friend CHRISTOPHER GRAHAM ELLIS) [2020] WASCA 147 (10 September 2020)

[2020] WASCA 147

Court of Appeal (WA)|2020-09-10|Before: Quinlan CJ

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Source facts

Court

Court of Appeal (WA)

Decision date

2020-09-10

Before

Quinlan CJ

Source

Original judgment source is linked above.

Judgment (619 paragraphs)

[1]

Cooper Ellis (the respondent) was born at 9.42 pm on 24 August 2009 at Bentley Hospital (the Hospital). The East Metropolitan Health Service (the appellant) is the legal entity responsible for the medical and nursing care provided by the Hospital, including that of Dr Hamza Amira, the obstetrician responsible for the management of the respondent's birth.
The respondent's birth was prolonged and difficult, in the course of which Dr Amira made a number of unsuccessful attempts to deliver the respondent by a Kiwi cup vacuum extraction, a form of instrumental delivery. When the respondent was ultimately delivered, via a combination of techniques, he was 'flat', meaning he was not breathing, not moving and showed poor muscle tone. It was not in dispute that the respondent suffered periods of perinatal asphyxia, meaning that, around the time of his birth, he suffered from a lack of oxygen or a lack of blood supply.[1]
The respondent claimed that he suffered significant injuries in the course of his birth process, and that those injuries were caused by the negligence of Dr Amira. There was no issue that the appellant was vicariously responsible for the actions of Dr Amira.
Gething DCJ found the respondent's case proven and, on 16 March 2018, ordered that judgment be entered for the respondent against the appellant in the sum of $5,231,149. There is no challenge to the assessment of damages.
The learned trial found that Dr Amira was negligent in the following respects:

[2]

[6]

There is no challenge to the findings of negligence.
His Honour also found that, in the absence of these breaches, the respondent would either have been safely delivered by the use of instruments or, if that did not occur after three pulls of a correctly placed instrument, safely delivered by caesarean section. In either case, the respondent would not have suffered the periods of perinatal asphyxia that he did.[6]
It was also not in dispute, at trial or on appeal, that as a consequence of the respondent's difficult birth, he suffered a number of injuries. The learned trial judge described the undisputed injuries as: perinatal asphyxia, global hypotonia, right sided Erb's palsy and renal impairment.[7] It may be open to debate whether perinatal asphyxia, as such, should be characterised as an injury (i.e. 'impairment' of a person's physical condition).[8] A lack of oxygen is perhaps better described as a physiological event, which may, or may not, result in an injury or impairment.
The other undisputed 'injuries' described by his Honour (global hypotonia, right sided Erb's palsy and renal impairment), however, clearly meet the description of damage, necessary to complete the cause of action in negligence. Accordingly, while those injuries were transient in nature, they nevertheless amounted to damage, which is the gist of an action in negligence.[9]
Nor, subject to some refinement of the issue we will set out later, is there any question that, as a consequence of the respondent's difficult and prolonged birth, he suffered an injury to his brain. The respondent pleaded that he had suffered hypoxic ischaemic encephalopathy and a traumatic brain injury as a result of the birth process.[10]
Hypoxic ischaemic encephalopathy (HIE) refers to an abnormal condition of the brain tissue (encephalopathy) caused by a lack of oxygen (hypoxia) in the blood supplying the tissue (ischaemia). A related term, an hypoxic ischaemic insult (HII), refers to the circumstance of insufficiently oxygenated blood getting to a particular part of the body, which, in turn, leads to damage to the tissue.[11]
That the respondent suffered injury to his brain, or indeed that he had suffered hypoxic ischaemic encephalopathy as a consequence of his birth process, was not in dispute at trial. As will be seen, it was the degree (or stage) of HIE that was in dispute.
None of the above matters are in issue in the appeal.
What is in issue in the appeal are what the learned trial judge described as the respondent's Developmental and Cognitive Impairments. The Developmental and Cognitive Impairments were:[12]

[13]

While the question as to the cause of the respondent's Developmental and Cognitive Impairments was a question of some factual complexity, it nevertheless concerned a relatively discrete and narrow issue.
It is surprising, then, that the appeal raises no less than 22 grounds of appeal. It is, recalling McHugh J's observation in Tame v New South Wales,[17] inherently unlikely that a question of causation such as this would give rise to 22 issues, or that a judge of the District Court would make so many errors. There is, in this regard, a considerable degree of overlap between the various grounds of appeal. In that context, it is worthwhile identifying a number of broad themes that emerge from the grounds and the appellant's submissions.
First, the appellant challenges a number of the primary facts found by the learned trial judge and his Honour's preference for the evidence and opinions of some of the witnesses over others.
For example, the learned trial judge found that the respondent had suffered moderate, or 'stage 2', hypoxic ischaemic encephalopathy.[18] His Honour also made the related finding that the respondent had suffered seizures during his admission at Princess Margaret Hospital.[19] In so finding, his Honour accepted the judgment of Dr Shripada Rao, the respondent's treating Neonatal Physician, who gave evidence at trial. His Honour gave detailed reasons for accepting Dr Rao's judgment. [20]
In conducting a 'real review' of the evidence given at trial in relation to these (and other) findings, the necessity for the appellant to identify error and the principles of appellant restraint must be steadily borne in mind. Those principles are grounded in the advantages possessed by the learned trial judge, not only in having seen and heard the witnesses but in the 'feeling of a case' that usually emerges from running a trial and an appreciation of the way the trial was run.[21]
Secondly, the appellant places much emphasis on the fact that the learned trial judge, particularly when addressing a number of the primary facts in isolation, made findings expressed in terms of what was 'possible'. Many of the grounds of appeal rely upon passages of the Primary reasons that refer to certain 'possibilities'.[22]
A good example of this is his Honour's finding that 'it is quite possible' that Magnetic Resonance Imaging (MRI) scans performed on the respondent in 2014 and 2015 showed damage to the respondent's brain that extended beyond the right cerebellar tonsil.[23] The appellant contends that the learned trial judge erred in law in finding that 'this possibility of damage was sufficient to prove a causal link between breach and the [respondent's] 'Developmental and Cognitive Impairments''.[24]
Whether his Honour in fact found that 'the possibility of [such] damage was sufficient to prove [such] a causal link' is very much open to question. Certainly there is no express finding by the learned trial judge to that effect. It will be important, therefore, in addressing the grounds of appeal to determine what, on a proper construction of the Primary reasons (including what can be legitimately inferred from the reasons),[25] his Honour, in fact, found.
Given the significance of both the factual issues and the proper construction of the Primary reasons for the resolution of the appeal, it is appropriate to commence with a summary of:

[25]

On 25 August 2009, the respondent also underwent a cranial ultrasound (Day 1 Ultrasound). The Day 1 Ultrasound showed evidence of cerebral oedema, namely excessive fluid in the brain substance.[38]
The progress notes for 26 August 2009 record the respondent as being 'very irritable most of the night' and also records 'no seizures overnight'. A later note records the respondent as 'jittery' and, at around 4.00 pm, nursing staff observed 'increasing jittery/seizure ? movements', in response to which phenobarbitone was administered 'to good effect'.[39]
On 26 August 2009, a registrar made a request to a consultant neonatologist for an opinion, which identified the presenting problems as including 'HIE' and seizures.[40]
Later that day a second EEG study was conducted on the respondent. He was 'irritable' throughout the study but no electrographic seizures were recorded. His temperature was 33.6 degrees.[41]
The progress notes for 27 August 2009 record the respondent as being jittery most of the night and occasionally irritable. He was given a further dose of phenobarbitone later in the day, with another note of 'no overt seizures'. The therapeutic hypothermia continued until midnight on 27 August 2009 when warming was commenced to bring the respondent up to a normal temperature.[42]
The progress notes for 28 August 2009 recorded that the respondent continued to be jittery and that there were no physical signs of seizures.[43] Similar entries appear for 29 August 2009, during which time the respondent was still being administered phenobarbitone.[44]
There were occasional references in the progress notes to the respondent being jittery in subsequent days but no obvious seizure activity was noted. By 31 August 2009, the respondent had developed good suck reflexes and was off intensive care support.[45]
On 31 August 2009, Dr Rao sent a consultation request to a neurology consultant. The reason for consultation was stated to be 'HIE' and the consultation request included the following:

[28]

Findings:

There is an area of haemorrhagic contusion involving the inferior margin of the right cerebellar hemisphere extending into the right flocculus. There is also minor haemorrhage within the inferior cerebellar tonsil which herniates below the foramen magnum to the C1/2 level.

A further area of haemorrhage is seen lying superior to the superior cerebellar vermis. There are multiple small petechial haemorrhages within the right cerebellar hemisphere.

There is subdural blood lining the tentorium cerebelli and evidence of subdural collections over both parieto-occipital convexities. This is slightly larger on the left measuring approximately 5mm in maximal depth.

Minor intraventricular blood is also seen within the dependent portions of both occipital horns and the third ventricle.

There also appears to be a tiny focus of petechial haemorrhage within the left superior temporal lobe. There is a further small focus of haemorrhage within the left side of the suprasellar cistern which I suspect subarachnoid in nature.

The DWI sequence demonstrates diffusion restriction at the site of the right inferior cerebellar haemorrhagic contusion. No other restricted focus is identified.

The cortical ribbon is preserved throughout.

The cerebral white matter volume and myelination is appropriate for a term baby. A small focus of increased T2 signal is seen within the left lentiform nucleus likely representing a VR space. The basal ganglia and thalami are otherwise normal. No abnormality is seen within the brain stem.

There is no evidence of hydrocephalus.

Note is made of a small right parietal cephalhaematoma.

COMMENT:

There is evidence of traumatic brain injury with an area of haemorrhagic contusion involving the right inferior cerebellar hemisphere extending into the flocculus and further haemorrhage within the cerebellar tonsil. There are foci of petechial haemorrhages within the right cerebellar hermisphere, a focus of parenchymal haemorrhage within the left superior temporal lobe and evidence of likely subarachnoid haemorrhage just superior to the superior cerebellar vermis and also within the left side of the suprasella cistern.

Shallow subdural haematomata are seen over both parieto-occipital convexities and minor haemorrhage is seen within the lateral and third ventricles.

No cortical or basal ganglia infarct is identified.

[152]

d. What could have caused the particular symptoms?

In my opinion, it is likely that Cooper's stormy neonatal history likely contributes to the pattern of cognitive vulnerabilities observed on testing. Cooper's medical records document that Cooper has been diagnosed with Grade II Hypoxic Ischemic Encephalopathy (HIE) with perinatal asphyxia. A number of studies have found that children with neonatal encephalopathy (NE) of hypoxic-ischemic origin were at increased risk of cognitive deficits. For instance, Robertson and colleagues (1989) found that while children with mild NE were normal, children with moderate NE at 5.5 years and 8 years post-birth had good receptive vocabulary and perceptual motor skills, but were significantly delayed with reading, spelling and arithmetic, and likely to be approximately 1 year below normal controls or those with mild NE. Similarly, Marlow and colleagues (2005) founded that children with who had moderate encephalopathy scored similarly with regards to overall intelligence, but scored significantly lower than comparison children in the language and sensorimotor scales, and with narrative and sentence memory on the NEPSY. Achievement was at a lower level.

Medical records also indicate that Cooper has a traumatic brain injury with findings on brain MRI identifying areas of damage within the cerebellar region. Cerebellar disorders can manifest with a range of cognitive impairments. For instance, Levisohn and colleagues (2000) found that children who had undergone resection of cerebellar tumours exhibited difficulties with initiation of language, verbal fluency and word findings difficulties, decreased story retrieval, deficits in sequencing, planning and maintaining set, and visual spatial deficits. It is noted that these children had intact development of cognitive abilities prior to resection of the cerebellar tumour, which is different than Cooper's history as he has not acquired these abilities, then lost them. Rather, his profile is one of delayed/slower development of skills.

Other contributing factors for Cooper's profile include his significant difficulties with attentional processing and auditory processing difficulties, which can contribute to difficulties with learning capacity, recall and retention of information.

Missed exposure to teaching (due to not being able to see material on the board secondary to possible visual acuity difficulties prior to Cooper prescribed glasses, and absences from therapy/school) can also contribute to gaps in early skills development.

Finally, Cooper's father reports a history of suspected ADHD and possible dyslexia, which may be contributing factors for Cooper's difficulties with academic achievement as the heritability of dyslexia is estimated to be around 40-80% (Schumacher et al, 2008) with some epidemiological studies suggesting a twofold increase in the risk for boys relative to girls (Rutter et al., 2004). Similarly, the heritability of ADHD has been estimated to be around 75% (Farone et al, 2005).

[154]

There has been extensive consideration of all relevant MRI scans that have taken of Cooper by an expert neonatal physician and neurologist and by an expert in paediatric radiology.
In responding to my questions would you please assume the following?
First, that Cooper's MRI scans at birth show very minor parenchymal injury and the scans at 5 years none.
Second, Cooper's MRI scans at birth show restricted diffusion in the right cerebellar tonsil and on the T1 and T2 weighted images in all planes, there is injury to the right cerebellar tonsil with some haemorrhage into this structure extending to the flocculus immediately adjacent to the cerebellar tonsil.
Third, the lesion in the right cerebellar tonsil is traumatic in origin and not the result of an embolic infarct.
Fourth, the MRI scans otherwise show that Cooper's brain is normal, with normal development and normal myelination. There is no impairment of myelination within the posterior limb of the internal capsule. There is no injury to the basal ganglia. There is normal corticomedullary differentiation.
Fifth, MRI scans done when Cooper was aged 5 years show encephalomalacia of the right cerebella tonsil with some extension into the right flocculus. Otherwise the brain is normal.
Sixth, isolated injury to a cerebella tonsil, is not consistent with known patterns of injury following hypoxic ischaemic encephalopathy.
Seventh, injury to the right cerebellar tonsil is not associated with any deficit in development or cognitive function. In fact, in isolation it does not cause any symptoms or deficit.
Eight, hypoxic ischaemic injury to the brain has 2 major patterns. First, in prolonged partial hypoxia, damage occurs in the cerebral cortex and the intervascular boundary zones (both the cortex and subcortical white matter) resulting in a watershed infarct. Second in an acute severe hypoxic ischaemic episode the pattern of damage is to the deep grey matter (thalami and basal ganglia), posterior brain stem and the motor cortex. These structures in Cooper's brain are normal.
Ninth, accordingly, there is no MRI evidence of an hypoxic ischaemic injury to Cooper.
Tenth, at trial, expert evidence will be given to the effect that the disabilities for which Cooper suffers are not consistent with the abnormalities seen on the relevant MRI images.
The learned trial judge observed that a number of these assumptions did 'seem to suggest the answer to the very question asked of Dr Do'.[181] This observation, to our mind, rather understates the effect of the solicitor's letter of instructions.
Dr Do's subsequent report, dated 24 August 2017, did indeed report a change in her views. She said:[182]

[207]

While the appellant did not, in its pleaded case, identify a specific alternative cause of the respondent's Developmental and Cognitive Impairments, the learned trial judge addressed a number of other potential causes or explanations raised by the evidence.
The first was a genetic issue. His Honour noted that Professor Hunt commented, almost in passing, that the respondent's global developmental delay 'may be accounted for by subtle underlying genetic abnormality' (see [165] above). In the absence of any evidence that any testing had occurred in relation to the suggestion, the learned trial judge did not regard this comment by Professor Hunt as comprising a plausible alternate hypothesis for the respondent's Developmental and Cognitive [220]airments.220
The second potential cause was ADHD (attention deficit hyperactivity disorder). In light of the evidence of Dr Pestell and Dr Do, his Honour concluded that the evidence did not establish that ADHD was a plausible alternate hypothesis for all of the respondent's Developmental and Cognitive Impairments.[221]
The third potential cause was the possibility, raised by Dr Do, that lack of sleep may have caused the respondent's problems with attention and inhibition. That suggestion did not, however, extend to all of the respondent's developmental and cognitive issues and his Honour concluded that lack of sleep was not a plausible alternate hypothesis for all of the respondent's Developmental and Cognitive Impairments.[222]
The learned trial judge also addressed the appellant's submission in closing that the respondent may well just be an ordinary child at the lower end of the relevant developmental spectrum. His Honour concluded that there was no basis in the evidence for that contention.[223]
Bringing these matters together, his Honour concluded that he did not consider that there was a plausible inference competing with the inference that the respondent's Birth Injuries caused or materially contributed to Cooper's Developmental and Cognitive Impairments.[224]
Finally, his Honour observed that, to the extent that ADHD (or any other alternative causes) may have been a cause of the respondent's Developmental and Cognitive Impairments, his Honour found that the appellant had not satisfied the evidential onus on it to disentangle the alternative causes.[225]

[208]

Based on, and drawing together all of, the matters referred to above, the learned trial judge found that the respondent's Developmental and Cognitive Impairments are more likely than not to be sequelae of his Birth Injuries, which were caused by the defendant's fault.[226]
This is the critical finding as to causation in this appeal. His Honour went on to summarise the reasoning behind that finding in eight points. It is appropriate to set out those points in full:
1. First, there is firm expert evidence that Cooper's Developmental and Cognitive Impairments are sequelae of Cooper's Birth Injuries. This is not a case in which the court is being asked to make a finding of causation where no expert is either able to do so, or prepared to do so. It is not a case in which where there is no expert evidence that rises above the 'possible'.
2. Second, to the extent that the expert evidence to the contrary is based on the premise that Cooper only sustained stage 1 HIE in the process of his birth, this premise falls away by reason of my finding that he sustained stage 2 HIE.
3. Third, it is the case that the injury to Cooper's brain most apparent on the MRI scans is to his right cerebellar tonsil, and that an injury of that kind only is unlikely to have caused Cooper's Cognitive and Developmental Impairments. However, it is quite possible that the injury to Cooper's brain is more widespread, in particular extending into some of the structures adjacent to the right cerebellar tonsil. This is a matter of interpretation of the relevant MRI images. Moreover, the fact that the 2014 MRI and 2015 MRI images do not show areas of damage to Cooper's brain beyond the area of the right cerebellar tonsil, and possibly adjacent structures, does not of itself mean that there is not wider damage to Cooper's brain. In particular, it is also quite possible that Cooper sustained a global microscopic brain injury.
4. Fourth, there is no compelling medical evidence to the effect that Cooper's Developmental and Cognitive Impairments are not sequelae of Cooper's Birth Injuries; only matters of interpretation and opinion. Rather, the medical evidence is to the effect that it is quite possible that Cooper's Developmental and Cognitive Impairments are sequelae of Cooper's Birth Injuries. In particular, if the injury to Cooper's brain extended beyond the right cerebellar tonsil into the adjacent structures of the cerebellum, in particular the vermis, left cerebellar tonsil, flocculus and right foramen of Luschka, then this has the potential to give rise to neurological and developmental impairments.
5. Fifth, there is well-established research to the effect that 50% or so of children with stage 2 HIE will go on to suffer from neurological and developmental issues. This is obviously not a basis for a finding that Cooper is in this 50%. However, it is a basis for a finding that it is quite possible that the fact that Cooper sustained stage 2 HIE caused or materially contributed to Cooper's Developmental and Cognitive and Impairments. The connection between stage 2 HIE and the types of impairments comprising Cooper's Developmental and Cognitive Impairments is well established, in particular where the HIE is accompanied by a traumatic brain injury.
6. Sixth, from a neuropsychological perspective, the pattern and nature of Cooper's Developmental and Cognitive Impairments are consistent with him having suffered serious damage to his brain, of a traumatic nature, soon after birth, in particular damage consistent with him sustaining HIE.
7. Seventh, this is not a case in which there is any other plausible inference competing with the inference that Cooper's Birth Injuries caused or materially contributed to Cooper's Developmental and Cognitive Impairments. It is not a case in which the court is left with two conflicting inferences, each of equal probability.
8. Eighth, to the extent that ADHD may be considered as a possible alternate cause of Cooper's Developmental and Cognitive Impairments, the defendant has not discharged the evidential onus on it to disentangle those causes, and show that Cooper's Birth Injuries did not materially contribute to Cooper's Developmental and Cognitive Impairments.
9. These reasons are ample to support a reasonable and definite inference that Cooper's Developmental and Cognitive Impairments are sequelae of Cooper's Birth Injuries and that the defendant's fault was a necessary condition of the occurrence of both Cooper's Birth Injuries and Cooper's Developmental and Cognitive Impairments. To the extent that some of the primary facts are in the realm of the possible, for example the full extent of the damage to Cooper's brain in the area of the right cerebellar tonsil, I am entitled to give 'weight to the united force of all the evidence together'.
His Honour added that, even if he was wrong in his conclusion that the defendant's fault was a necessary condition of the occurrence of the respondent's Developmental and Cognitive Impairments, the reasons he had set out were more than ample to support a reasonable and definite inference that the appellant's fault materially contributed to the respondent's Developmental and Cognitive Impairments for the purposes of s 5C(2) of the Civil Liability Act. His Honour stated that a finding of material contribution is a sufficient reason why responsibility for both the respondent's Birth Injuries and Developmental and Cognitive Impairments should be imposed on the appellant for the purposes of s 5C(2)(a) and (b) that Act.[227]

[210]

As noted above, the appellant's grounds of appeal are legion. They are as follows:
1. The trial judge erred in law by construing the word harm in s.5C(l) of the Civil Liability Act 2002 to include the possibility of personal injury; [648]-[651], [935], [936], [946], [948].
2. The trial judge erred in law in concluding that expert evidence stating the possibility of a causal link between fault and harm is sufficient to prove a causal link between fault and harm; [815], [817], [818], [895], [935], [936].
3. The trial judge erred in law by finding that the plaintiff's 'brain injuries' were 'traumatic' based on material that was not in evidence at trial and which the defendant could not consider; [37], [653]-[663].
4. The trial judge erred in law and fact by not making a finding as to whether the haemorrhagic contusion to the right cerebellar tonsil extended into adjacent structures, including the flocculus, vermis, left cerebellar tonsil and adjacent cerebellar hemisphere; [648]-[651], [933], [936], [938].
5. The trial judge erred in law in finding that 'it is quite possible' that the 2014 and 2015 MRI scans showed damage to the plaintiff's brain that extended beyond the right cerebellar tonsil to the adjacent structures of the cerebellum, in particular the vermis, left cerebellar tonsil, flocculus and right foramen of Luschka which damage was caused by a breach of duty by the defendant; and that this possibility of damage was sufficient to prove a causal link between breach and the plaintiff's 'Developmental and Cognitive Impairments'; [852(b)], [862], [910], [935], [936], [941], [946], [948].
6. The trial judge erred in law in finding that it was 'quite possible' that the plaintiff sustained a global microscopic brain injury caused by a breach of duty of the defendant; Judgment [880], [935], [936], [937], [938], [941], [946] and [948].
7. The trial judge erred in law by not addressing an issue which had to be addressed in order to determine the case; being that classification of the plaintiff as suffering from moderate or stage 2 hypoxic ischemic encephalopathy (HIE) was irrelevant to determining whether any of the plaintiff's 'Developmental and Cognitive Impairments' were caused by any breach of duty by the defendant; [664]-[704], [933], [934], [937], [941], [946], [948].
8. In the alternative to Ground 7, if relevant to find whether the plaintiff suffered at any time from HIE stage 2, the trial judge erred in fact in so finding; [664]-[709], [933], [934], [937], [938], [941], [966], [968]. The finding is against the weight of the evidence.
9. The trial judge erred in fact by (in effect) finding that the plaintiff suffering a right sided Erb's palsy was relevant to breach causing 'Cooper's Developmental and Cognitive Impairments'; [590], [709], [790], [932], [933], [935], [936], [941], [946], [948].
10. The trial judge erred in fact by (in effect) finding that the plaintiff suffering renal impairment was relevant to breach causing 'Cooper's Developmental and Cognitive Impairments'; [709], [790], [932], [933], [941], [946], [948].
11. The trial judge erred in fact in finding that Dr Nguyen gave evidence to the effect that the first (Day 7) MRI showed injury to the left cerebellar tonsil; [614], [616], [935], [941], [946], [948].
12. The trial judge erred in fact by finding that minor subdural haemorrhage and intraventricular haemorrhage seen in the Day 7 MRI were caused by any breach of duty by the defendant and caused the plaintiffs 'Developmental and Cognitive Impairments'; [709], [663], [933], [935], [939], [941], [942], [946] and [948].
13. The trial judge erred in law in finding that there existed 'clear expert evidence' that the plaintiff's Developmental and Cognitive Impairments were, in terms of s.5C(1) of the Civil Liability Act 2002, caused by a breach of duty of the defendant; [891], [894], [933], [939], [941], [946] and [948].
14. The trial judge erred in fact in preferring the evidence of Dr Tracy to that of Professor Hunt that the plaintiff's Developmental and Cognitive Impairments were caused by the plaintiff's Birth Injuries; [892], [933], [937], [941], [946], [948].
15. The trial judge erred in fact in finding that there was a consensus between expert witnesses that, of children classified as stage 2 HIE, 50% (or so) suffered from neurodevelopmental deficits and 50% (or so) did not; [893], [934], [937], [941], [946], [948].
16. The trial judge erred in law in finding that the fact that 50% (or so) of children with HIE stage 2 suffer from neurodevelopmental deficits is a basis for a finding that it is 'quite possible' that the plaintiff suffered from stage 2 HIE which caused or materially contributed to his Developmental and Cognitive Impairments; [894], [934], [937], [941], [946], [948].
17. The trial judge erred in law in determining that, for s.5C(2) of the Civil Liability Act 2002, it is an established principle that, as a matter of ordinary common sense and experience, negligence 'materially contributed' to and thereby caused harm; [718]-[720], [894], [914], [926], [931], [937], [939], [941], [946] and [948].
18. The trial judge erred in law by imposing a burden upon the defendant to disprove that, in terms of s.5C(l)(b) and s.5C(4) of the Civil Liability Act 2002, this case was an appropriate case for the scope of the defendant's liability to extend to the harm so caused; [743], [937], [939], [941], [942], [945], [946], [948].
19. The trial judge erred in law by determining that in terms of s.5C(l)(b) and s.5C(4) of the Civil Liability Act 2002 there existed well-established precedent, with which this matter was consistent, that rendered the scope of liability for the consequences of the harm coextensive with the content of the duty of the defendant which has been breached; [743], [941], [946], [947], [948].
20. The trial judge erred in law in concluding that there exists a principle of law that a significant circumstance in favour of drawing an inference of causation is that a defendant has not established or suggested an alternative cause; [813], [939], [941], [946], [948].
21. The trial judge erred in law and in fact in finding that it is not possible that the plaintiff is a child at the lower end of the developmental spectrum; [925].
22. By reason of Grounds 1-21 the trial judge erred in making the finding at [946] and [948].
Before turning to the individual grounds of appeal, we commence with the broad construction of the learned trial judge's reasons, in light of the accepted principles in relation to inferring causation and the relevance of evidence of 'possibilities'.
It is to those principles that we first turn.

[215]

As this passage also makes clear, the law's concern, in relation to causation, is with the attribution, in a particular case, of a causal connection between an identified negligent act or omission (or other wrong) and a given occurrence. In the context of the present case, for example, the question was whether, on the balance of probabilities, the identified negligence (for which the appellant was responsible) was the cause of the respondent's given (or known) Developmental and Cognitive Impairments.[232]
To be clear: the question in the present was not whether, in general, negligence of the kind that occurred in the present case is more or less likely to give rise to the kind of Developmental and Cognitive Impairments suffered by the respondent. No doubt that general question - the answer to which will be given by medical science - may be of importance (and may indeed be decisive) in a given case. But it would be a mistake, and potentially misleading, to confuse that scientific question with the legal one.
An example from the present case may perhaps illustrate this point. As is apparent from the above summary of the expert evidence, much attention was given, in the present case, to the likelihood of a child with stage 1 or stage 2 HIE going on to experience neurological deficits. The learned trial judge, for example, referred to the research to the effect that 90% of infants with stage 1 HIE would be expected to have a normal neurodevelopmental outcome, a percentage which reduced to 50% of infants with stage 2 HIE.[233]
One might draw from these general statistics the proposition that, as a matter of prediction (or prognosis), a child who suffers stage 1 HIE will have only a 10% chance of developing neurological deficits. It is necessary to be clear, however, what this general statistic does not mean. It does not mean that, in the case of a child who has suffered stage 1 HIE and has known neurological deficits, there is only a 10% chance that the former caused the latter.
That is a matter of basic logic and mathematics. The fact that the probability that a given event will cause an adverse outcome is unlikely (say 10%) does not necessarily mean that the probability that such an outcome was caused by that event is equally unlikely (or indeed that it is unlikely at all).
To take a simplified example, it may be that, as a matter of medical science, a particular medical condition (disease X) has only one possible cause (cause Y), such that all cases of disease X would be caused by cause Y. The probability of cause Y given disease X would be 100% (i.e. P(Y|X) = 100%). That causal relationship, however, does not say anything about the probability that a person exposed to cause Y will develop disease X. It may, for example, be that only 10% of persons exposed to cause Y will develop disease X (i.e. P(X|Y) = 10%). It is not possible, therefore to reason simply from the fact that P(X|Y) is unlikely that P(Y|X) is also unlikely.
As French CJ explained in Amaca v Booth,[234] an after‑the‑event inference of causal connection may be reached on the balance of probabilities notwithstanding that the statistical correlation between the first event and the second event indicated, prospectively, no more than a 'mere possibility' that the second event would occur given the first.
It is in this context (namely, the determination of factual causation) that the relevance of 'possibilities' revealed by the evidence arises for consideration.
In this regard, it is clear, and there can be no doubt, that mere proof by a plaintiff of the possibility that a defendant's breach caused the plaintiff to suffer harm is insufficient. The court must be satisfied that it is more probable than not that the defendant's breach caused the relevant harm; it is not sufficient to conclude that the breach may have been a cause of the harm.[235]
At the same time, it is also well‑established that causation may be proved by inference. If direct proof is not available, an inference of causation may be drawn if the circumstantial evidence is sufficiently strong and coherent to support a definite inference to that effect.[236] Before such an inference can be drawn, there must be more than two conflicting inferences of equal probability.[237]
The drawing of an inference has been described as 'an exercise of the ordinary powers of human reason in the light of human experience'.[238] A court must, of course, avoid conjecture, but the distinction between permissible inference and conjecture occurs on a continuum in which there is no bright line division.[239]
Accordingly, even if other disciplines may not be able to give a conclusive answer, questions of causation, as a step in the determination of liability in negligence, call for 'sufficient reduction to certainty to satisfy the relevant burden of proof for the attribution of liability'.[240]
There will, no doubt, be cases where expert evidence of a scientific or medical nature (where it is accepted) will preclude a finding of causation. As Dixon J said in Adelaide Stevedoring Co Ltd v Forst,[241] in a paragraph cited with approval by the plurality in Amaca v Booth:[242]

[229]

It must be recognised in this context that, notwithstanding the comprehensive nature of the Primary reasons, there are certain matters (in terms of the learned trial judge's findings) that must be inferred from the Primary reasons as a whole.
For example, given the finding that an injury to the right cerebellar tonsil alone was unlikely to have caused the respondent's Developmental and Cognitive Impairments, and his Honour's ultimate finding that the injury to the respondent's brain did, more likely than not, cause those impairments, it must follow, as a matter of logic, that his Honour was satisfied that the injury to the respondent's brain was not confined to the right cerebellar tonsil and that he had sustained further injury to his brain (either to the cerebellum or more globally).
In response to this proposition the appellant observed, not without some justification: 'well, except that he didn't say that'.[265]
With respect to the learned trial judge, there is merit in this observation. His Honour did not make an express finding, in terms, that the respondent had sustained injuries to his brain beyond the right cerebellar tonsil. And given the significance of the issue (at least to the appellant), in our view, it would have been preferable if his Honour had done so. Again, and with respect to the learned trial judge, it would ordinarily be expected that a factual issue of this significance would not be left to be inferred from the reasons.
Nevertheless, and notwithstanding that criticism of the Primary reasons, the real issue for present purposes, is whether, on a proper construction of the Primary reasons, his Honour implicitly so found. That is: should it legitimately be inferred from the Primary reasons that his Honour was satisfied that the injuries to the respondent's brain consequent upon the appellant's negligence were more extensive than the injury to the right cerebellar tonsil?[266]
In our view, this is the proper construction to be given to the Primary reasons. The learned trial judge must be taken to have found that the injuries to the respondent's brain were more extensive than the injury to his right cerebellar tonsil. As explained in [311] below, this may have occurred in (either or both of) at least two different ways - either because the traumatic injury to the cerebellum went beyond the right tonsil, or because there was a global microscopic injury.
So much is to be inferred from the matters identified at Primary reasons [935] and [936], in which his Honour refers to the evidence as to the potential for more widespread injury to the respondent's brain, as identified by the expert evidence called by the respondent, in contradistinction to the evidence as to the injury to the right cerebellar tonsil. In the circumstances, the combination of those findings, together with the other circumstances identified by his Honour at Primary reasons [933] to [940], are such that, to paraphrase Barwick CJ's formulation in Tubemakers v Fernandez, the other circumstances united to warrant a conclusion that what the medical evidence established as a possible cause was the probable cause of the respondent's Developmental and Cognitive Impairments.[267]
In this regard, it is important to notice that the implicit finding identified in [292] above is not, as some of the appellant's submissions tended to suggest was necessary, a step towards the ultimate conclusion, by inference, that the injury to the respondent's brain caused the respondent's developmental and cognitive impairments. Rather, it is a finding implicitly made in so concluding.
In other words, expressed in the language of criminal law jurisprudence, a finding that the injuries to the respondent's brain were more extensive than the injury to his right cerebellar tonsil was not an intermediate fact - it is not an indispensable link in a chain of reasoning towards the ultimate conclusion.[268] The position was explained by McLure P in Austic v The State of Western Australia:[269]

[234]

In construing the Primary reasons, it should be recognised that there were a number and variety of medical 'possibilities' identified and found by his Honour, to which his Honour had regard. Those findings as to the various 'possibilities' reflected different kinds or types of uncertainty or contingency.
For example, one kind of 'possibility' was the possibility arising from the epidemiological research in relation to the outcomes of children diagnosed with the various 'stages' of HIE.[271] Findings of this type are expressed in terms of possibility because of the nature of epidemiological research.[272]
Another kind of 'possibility' was the possibility arising from the limitations of MRI imaging itself. As his Honour expressly found, the absence of visible injury on an MRI does not necessarily mean that no injury is present. That is, there may be injuries to the brain that are not 'picked up' on MRI but which are clinically present. His Honour so found.[273]
The possibility, for example, of a global microscopic brain injury was therefore one found by his Honour, in part, because of the limitations of MRI imaging. It is not dependent upon a difference of opinion or interpretation of the imaging itself.
By contrast, a third kind of 'possibility' found by the learned trial judge was the consequence of what his Honour described as 'matter of interpretation and opinion on which experts may legitimately differ'.[274] This was clearly the case in relation to his Honour's findings that it was 'quite possible' that the haemorrhagic contusion to the area of the right cerebellar tonsil extended beyond the right cerebellar tonsil into the adjacent structures, including the flocculus, vermis, left cerebellar tonsil and adjacent cerebellar hemisphere.[275]
That finding was clearly based upon the evidence of Dr Keenan (and, in some respects Dr Nguyen[276] and Professor Hunt[277]), who identified those features on his examination of the Day 7 MRI. Expressing a finding such as this in terms that it was 'quite possible' requires some unpacking.
In understanding this finding, it should first be observed that it is not an expression of 'mere' possibility arising as a hypothesis in the absence of evidence.[278] It was a specific finding based on evidence from expert witnesses as to the content of the MRI scan. In that sense, in our view, his Honour's characterisation of the extension of the injury beyond the right cerebellar tonsil as 'quite possible', should be understood in the sense of 'distinctly possible', 'rationally plausible' or a 'plausible hypothesis'. It did not, as the appellant suggests, mean 'possible in the sense of ... a spaceship landing on the front lawn'.[279]
Secondly, it was a finding based on the evidence of an expert (Dr Keenan) who the learned trial judge found to be a very experienced radiologist[280] and whose evidence his Honour evidently accepted as reliable and credible. The identification of the abnormalities identified by Dr Keenan as 'quite possible' necessarily involved acceptance of his opinion evidence to that extent.
Thirdly, it was also necessarily a finding to the effect that Professor Ditchfield's evidence (which was contrary to Dr Keenan's evidence in this regard) did not satisfy the learned trial judge that he could exclude, as an available hypothesis, that the injury to the cerebellum extended beyond the right tonsil to the adjacent structures. The reference to more extensive injury being 'quite possible'[281] must be understood by reference to the finding that reviewing an MRI scan is a matter of interpretation and opinion on which experts may legitimately differ.[282] It is implicit in his Honour's reasons that both Dr Keenan's and Professor Ditchfield's interpretations of the Day 7 MRI were legitimate and reasonable interpretations of the image. The possibility arose from the learned trial judge's conclusion that a legitimate interpretation of the Day 7 MRI was that it showed the haemorrhagic contusion extending into structures including the vermis.
Fourthly, and most importantly, the finding that the additional abnormalities identified by Dr Keenan were 'quite possible' was expressed as a 'primary' factual finding, in isolation from all of the other evidence. This is clear from the structure of the Primary reasons as a whole, in which the learned trial judge addressed each of the relevant circumstances separately and individually, before arriving at his ultimate findings. It is reflected in the manner in which, in the introductory summary, his Honour foreshadowed his finding that '[d]rawing all the threads together, a reasonable and definite inference may be drawn' as to the ultimate factual causation question.[283] It was also made clear in the Primary reasons at the point at which his Honour stated his ultimate conclusion (where his Honour referred to some of the 'primary facts' being in the realm of the possible).[284]
The fact that there were a number of primary facts which, alone, did not rise above the level of possibility, may serve to explain why the finding that the injuries to the respondent's brain were more extensive than the injury to his right cerebellar tonsil was left to be inferred from the Primary reasons as a whole.
That is because, as is likely the case, the learned trial judge did not specifically find in what way the respondent's injury so extended. In that regard, there were a number of 'possibilities' as to how, or in what way, the respondent sustained brain injuries other than to the right cerebellar tonsil in such a way as to cause the respondent's Developmental and Cognitive Impairments.
To take the clearest examples, the learned trial judge found, as separate and distinct possible mechanisms of injury:

[237]

If either (or both) of these mechanisms had occurred the injuries to the respondent's brain could properly be said to have been more extensive than an injury to his right cerebellar tonsil. In addition a finding that either (or both) of them did occur would, together with other matters relied upon by the learned trial judge (stage 2 HIE, the pattern and nature of the impairments, and the absence of any other plausible inference), be a sufficient basis for a finding of factual causation between the appellant's negligence and the respondent's Developmental and Cognitive Impairments.
In the context of the issues in the trial, it was not necessary for his Honour to be satisfied which of the two (or more) possible mechanisms of injury was present in the respondent's case. That is, while his Honour was required to be (and was) satisfied, on the balance of probabilities, that the necessary causal link between the appellant's negligence and the respondent's Developmental and Cognitive Impairments was established, his Honour did not have to find the precise physiological mechanism that formed that link.[287]
It is significant, in that regard, that on the facts of this case, whichever precise mechanism gave rise to the respondent's Developmental and Cognitive Impairments, the appellant's negligence was responsible for each of them.
In some cases, of course, the precise mechanism for the development of a particular injury may be crucial. This will be the case, for example, where one mechanism of injury can be attributed to the negligence of the defendant and the other mechanism (or other mechanisms) cannot be. Amaca v Ellis was such a case, in which the exposure to two carcinogens (tobacco smoke and asbestos) may have caused the respondent's lung cancer, but only one of them (asbestos) was actionable. In those circumstances it was necessary for the court to be satisfied that one of the mechanisms (asbestos) was more probable than the other.[288]
In the present case, it was not necessary for the learned trial judge to find precisely how (in the sense of injury to which part of the respondent's brain) the appellant's negligence was the probable cause of the respondent's Developmental and Cognitive Impairments, so long as the primary facts found by his Honour supported a reasonable and definite inference that there was such a causal link and that his Honour drew that inference.
Clearly, in our view, the latter is what his Honour did.
It will be apparent from these observations that, when the Primary reasons are properly construed, and read as a whole, the learned trial judge did not find that the mere possibility of a causal link between the appellant's negligence and the respondent's injuries (and in particular his Developmental and Cognitive Impairments) was sufficient to prove factual causation under s 5C(1)(a) of the Civil Liability Act. Insofar as the grounds of appeal are premised upon the proposition that his Honour did so, we reject that premise.
We turn now to the individual grounds of appeal. For reasons that will become apparent, we have altered the order of them slightly to better reflect the logical order in which they arise for consideration.

[271]

Thus it is clear that the failure of a trial judge to disclose material to the parties, where that material is used to make a finding of fact in relation to a matter in issue, may amount to a denial of natural justice. In such a case, the relevant finding of fact is liable to be set aside on appeal.
The use of Mosby's Medical Dictionary by the learned trial judge to provide a definition of 'traumatic' as pertaining to an injury is, however, not such a case. His Honour did not use a medical text to reach a conclusion as to a disputed question of fact or to resolve conflicts in the evidence. Rather, the learned trial judge merely referred to a dictionary definition of a term used in the evidence and his reasons. Although his Honour referred to a medical dictionary, the definition of an ordinary English term was not materially different to that available from reference to a standard dictionary such as the Macquarie Dictionary.
The dictionary definition of 'traumatic', with respect, added nothing to the evidence adduced by the parties as to the use of 'traumatic'. In particular, the appellant's submission on this ground, that '[t]here is no basis for the finding that [the respondent] suffered traumatic brain injuries and no basis for the findings at [663] or [938]',[309] must be rejected.
Contrary to this submission, every expert witness who gave evidence relevant to the issue was of the view that the injuries to the respondent's brain shown in the Day 7 MRI were traumatic injuries sustained in the process of his birth. While there were, no doubt, differing views expressed as to the extent of those injuries (and whether they were evident on the MRI scans), all of the experts were agreed that those injuries were traumatic.
In this context it should be recognised that the term 'traumatic' was specifically used to describe injuries shown on the Day 7 MRI that occurred as a result of the physical processes of the respondent's instrumental birth (i.e. the traction on the tissues and blood vessels leading to haemorrhage and other visible damage).[310] In this regard, the term 'traumatic' was used in contradistinction to the injury caused to the respondent's brain by a lack of oxygen (perinatal asphyxia), namely hypoxic ischaemic encephalopathy.
Without attempting to be exhaustive, for example, in relation to the witnesses called by the respondent:

[283]

As discussed above (see [311]), there were at least two different possible mechanisms supported by the expert evidence, as to how, or in what way, the injuries to the respondent's brain went beyond the right cerebellar tonsil in such a way as to cause the respondent's Developmental and Cognitive Impairments. So long as the learned trial judge was satisfied, on the balance of probabilities, that one or more of those mechanisms had in fact come to pass, it was not necessary (on the facts of the present case) for his Honour to make a definite finding as to which one of them had done so.
This is particularly so, given that the respondent's case was that his Developmental and Cognitive Impairments arose from a combination of traumatic brain injury and hypoxic ischaemic encephalopathy.
It is in this way that, in our view, ground 4 misses the mark. The ground of appeal proceeds upon the assumption that the only way in which the respondent's Developmental and Cognitive Impairments could have been caused by his birth process was if they extended into the adjacent structures in the cerebellum.
That is, the appellant's case, in this regard, focusses entirely on the disagreement between the radiological experts as to the extent of the changes to the respondent's cerebellum visible on the MRI scans. Put another way, it proceeds upon the basis that if the learned trial judge accepted Professor Ditchfield's evidence that the MRI scans did not show any injury beyond the right cerebellar tonsil, the respondent's case was therefore bound to fail.
This assumption, with respect, takes too narrow a view of the respondent's case at trial and too narrow a view of the Primary reasons. The respondent's case was not confined to an allegation that the injuries that were visible on the MRI scans, and those injuries alone, were what caused the respondent's Developmental and Cognitive Impairments. Neither the respondent's pleading[321] nor the manner in which he put his case at trial so confined the respondent's case.
On the contrary, the witnesses called by the respondent emphasised the combined effect of all of the investigations (including MRI and ultrasound) and the entirety of the clinical picture, including the respondent's clinically diagnosed hypoxic ischaemic encephalopathy. Indeed, insofar as the expert evidence called by the respondent accepted that the damage evident on the MRI was 'traumatic' (in the sense discussed at [354] above) their opinions in relation to the effect of the respondent's HIE were unaffected by the disagreement as to what was visible on the MRI scans.
Indeed, every expert witness (including the witnesses called by the appellant), confirmed, in essence, that a 'normal MRI does not necessarily equal a normal brain'.[322]
Accordingly, it might have been open to find, on the balance of probabilities, that the respondent's Developmental and Cognitive Impairments were caused by his traumatic birth based on the clinical symptoms and diagnosis of HIE alone (i.e. even if he had a completely normal MRI). That was certainly the view of Dr Tracy, who based his conclusions on the clinical presentation of stage 2 HIE rather than the MRI scans.[323]
Of course, the prospect of such a finding did not arise in the present case because, on any view, the respondent did not have a 'normal MRI'. The presence of abnormalities evident on the MRI (whether expressed as probabilities or possibilities) were therefore simply further strands in the overall circumstantial case, to be assessed together with all of the other circumstances.
The fact, emphasised by the appellant on appeal, that in opening and closing submissions to the learned trial judge the respondent invited his Honour to make a positive finding - based on Dr Keenan's evidence - that the contusion to the cerebellum extended beyond the right cerebellar tonsil, did not mean that the respondent's case depended on such a finding being made. It was open to the learned trial judge to consider the cumulative force of the evidence as a whole in the manner that he did and, in doing so, to draw the conclusion that he did as to the competing expert opinions.

[284]

At the hearing of the appeal, while the appellant placed a great deal of emphasis on Professor Ditchfield's evidence as to what he could, or could not, see on the MRI, it ultimately accepted that Professor Ditchfield was not saying 'because it's not there, it could never be there'.[324] That acceptance was consistent with Professor Ditchfield's evidence at trial.[325]
Professor Ditchfield's evidence, therefore, did not preclude a finding of causation on the balance of probabilities. Indeed, the manner in which Professor Ditchfield's reports and his evidence developed over time were revealing as to what conclusions could be drawn from the MRI evidence alone.
Professor Ditchfield's first report was quite categorical: 'In this case, these structures are normal and there is therefore no MRI evidence of a hypoxic ischaemic injury'.[326] While the opinion quite properly refers to 'no MRI evidence' there is no suggestion in the report that there could be any other basis for diagnosing a hypoxic ischaemic injury.
The same is true of Professor Ditchfield's second and third reports, which confine themselves to reference to the MRI scans.[327]
Professor Ditchfield's fourth report, having received Dr Keenan's report, also in no way accepted that the respondent had suffered a hypoxic ischaemic injury, referring to Dr Keenan's view as 'speculative'. Perhaps surprisingly in this context, Professor Ditchfield noted that he had not seen the Day 1 Ultrasound but offered comment as to how it might be interpreted in any event.[328]
It was not until he received the Day 1 Ultrasound that, in his final report, Professor Ditchfield recognised that the respondent had experienced a 'prolonged partial hypoxic episode'.[329]
Even then, Professor Ditchfield proffered the opinion that the hypoxic insult occurred at least 24 hours prior to delivery. In this way, while he ultimately accepted that there had been a hypoxic ischaemic insult, Professor Ditchfield suggested that it was unrelated to the respondent's birth.[330] No other expert suggested the possibility of a hypoxic event (asphyxia) 24 hours prior to delivery.[331]
Contrary to Professor Ditchfield's opinion in this regard, the learned trial judge expressly rejected the proposition that the respondent had suffered a hypoxic event in the 24 hours proceeding his birth. His Honour found on balance that he had not.[332] The appellant does not challenge that finding.
Accordingly, in assessing the combined effect of all of the circumstances, including the clinical and ultrasound evidence of hypoxic ischaemic encephalopathy, it is significant that the learned trial judge had rejected Professor Ditchfield's evidence as to the cause of the respondent's HIE.

[286]

Given that conclusion, the only circumstance in which the learned trial judge would have been required to make a definitive finding, as between Professor Ditchfield and Dr Keenan, in relation to the interpretation of the MRI scans, would have been if a finding that Professor Ditchfield was correct would have prevented the learned trial judge from drawing an inference of causation based on all of the circumstances. Conversely, that could only have been the case if acceptance of the evidence of Dr Keenan that the damage to the right cerebellar tonsil extended into adjacent structures of the cerebellum was indispensable to a finding of causation.
For the reasons set out above, a finding of such damage was not an essential or indispensable link in the chain of reasoning towards an inference of causation. Rather, it was sufficient that the possible involvement of the adjacent structures (in addition to the other possible mechanisms to explain a broader brain injury) was one of the many strands in the cable. Another was that the respondent had suffered a global microscopic brain injury as a result of his HIE.
All of the authorities relied upon by the appellant in relation to this ground were authorities dealing with the duty of a trial judge to give adequate reasons for his or her decision, including in relation to the resolution of disputes between expert witnesses.[333] As those authorities make clear, where a trial judge prefers the evidence of one expert over another, he or she should give adequate reasons for that preference, even if it is simply that the judge, having seen and heard the witnesses, considered one more authoritative than the other.
The appellant's complaint on this ground, of course, was somewhat different. The appellant does not complain that the learned trial judge did not give adequate reasons for preferring one expert (Dr Keenan) over the other (Professor Ditchfield). Rather, it complains that his Honour did not make a finding as to which evidence he preferred, when his Honour was required to do so.
In that regard, as the Victorian Court of Appeal said in Fletcher Construction v Lines Macfarlane & Marshall:[334]

[290]

Nevertheless, in a contest between witnesses, such as that between Dr Keenan and Professor Ditchfield as to the interpretation of the MRI scans, it might reasonably have been expected that the learned trial judge would reach a finding in relation to whose evidence he preferred. It would have been preferable for his Honour to have done so. In a case such as the present, such a finding would have the potential, at least, to be relevant to an appeal (depending upon the conclusions that might be reached by an appeal court in relation to other findings of fact).
In this context, in our respectful view, his Honour discounted (or at least undervalued) his own advantage as the trial judge by his conclusion that there was no 'rational basis in the evidence before me to be able to prefer the evidence of one over the other'.[335]
The learned trial judge had the advantage of seeing and hearing the witnesses give their evidence. His Honour's own impression of the way in which they gave their evidence, together with the consistency of that evidence with other evidence, were all rational bases by which his Honour could arrive at a preference for one expert over another. Other bases existed, including those advanced by the appellant.[336]
It is also notable that there were other aspects in which his Honour preferred Dr Keenan's (and other experts') opinions over that of Professor Ditchfield. We have, for example, referred to the learned trial judge's rejection of Professor Ditchfield's opinion, once he had accepted that the respondent suffered a hypoxic ischaemic insult, that the insult occurred at least 24 hours prior to the respondent's birth (see [377] to [384] above). The rejection of Professor Ditchfield's opinion in this regard would itself have provided a rational basis for preferring Dr Keenan's evidence more generally.
Sometimes, of course, resolving differences in expert evidence will pose particular difficulties. In the present case, as the learned trial judge remarked, it may have been preferable, when particular disputed features of the MRI were being identified, for both experts to be present. Nevertheless, a trial judge's task is 'to endeavour to reconcile and grapple with the competing views as best' as he or she can in the circumstances.[337] In so doing a trial judge should not be timorous in using his or her full advantage in seeing and hearing the expert witnesses to resolve their competing views where there is no other way of doing so. Not only must an appeal court give respect to the advantage of the trial judge; the effective discharge of the appeal court's function will often depend upon it.

[292]

Thus, in the abstract, there were rational bases upon which the learned trial judge could have arrived at a preference for the opinion of one of these witnesses over the opinion of the other. However, the learned trial judge was not speaking in the abstract. His Honour was speaking by reference to the evidence and, understood in context, by reference to his evaluation of the competing evidence in the case as a whole. His Honour should be taken to have meant that, having seen and heard the witnesses giving their evidence, he did not find a basis, satisfactory to his mind, to resolve the conflict as to the interpretations of the MRI. That is, his Honour was not persuaded that one interpretation could be said to be wrong and the other right; both interpretations were reasonable and legitimate.
In finding that it was quite possible that the contusion to the right cerebellar tonsil extended beyond that tonsil into the adjacent structures,[338] the learned trial judge found, in effect, that Dr Keenan's interpretation of the MRIs to that effect was reasonable and legitimate. It was also implicit in this finding that Professor Ditchfield's interpretation of the Day 7 MRI, while also reasonable and legitimate, did not exclude the presence of those abnormalities as an available hypothesis.
Moreover, in the final analysis the learned trial judge essentially followed the same path of reasoning, and drew the same inference, as that drawn by Dr Keenan and Dr Tracy. In that regard, like those witnesses, his Honour considered all of the known facts and circumstances and was persuaded that their combined force sustained an inference of factual causation of the respondent's Cognitive and Developmental Impairments.
Therefore, in the permissible manner in which the learned trial judge resolved the case, it was not necessary for his Honour to reach a final conclusion as to which of the competing reasonable and legitimate interpretations of the Day 7 MRI (that it did and did not show damage to the structures adjacent to the right cerebellar tonsil) were to be preferred. While the learned trial judge did not expressly say that it was not necessary to reach a conclusion on that question, his Honour evidently considered it unnecessary, as he proceeded to determine the case without coming to a view on the balance of probabilities as to that question. While it would have been conducive to clarity, and distinctly preferable, for the learned trial judge to have expressly said that it was unnecessary (and to explain why), it was not an appellable error for his Honour not to have done so.

[305]

Ground 5 contends that the learned trial judge erred in law in finding that 'it is quite possible' that the 2014 and 2015 MRI scans showed damage to the plaintiff's brain that extended beyond the right cerebellar tonsil to the adjacent structures of the cerebellum, which damage was caused by a breach of duty by the appellant and that this possibility of damage was sufficient to prove a causal link between breach and the respondent's Developmental and Cognitive Impairments.
Ground 5 alleges an error of law. It is, in essence, the same error alleged in grounds 1 and 2 but more specifically directed to the extent of the injury as revealed on the 2014 MRI and the 2015 MRI. The relevant finding of his Honour as to that 'possibility' is set out at [220] and [221] above.
The appellant's submissions as to the error include the following:[339]
1. The reasoning in respect of the 2014 and 2015 MRI scans appears to be as follows. First, 'it is quite possible' that the 2014 and 2015 MRI scans show damage beyond the right cerebellar tonsil; [857]. Second, such damage is capable of causing neurological and developmental impairments, including the plaintiff's Developmental and Cognitive Impairments; [857], [862], [936]. Third, this possibility of this capability is relevant to inferring that the plaintiff's Birth Injuries caused his Developmental and Cognitive Impairments; [936].
2. The logic is; it is possible that X exists. X is capable of causing Y. Y exists. Therefore, X caused Y.
We reject ground 5, essentially for the reasons we have given in the relation to grounds of appeal 2 and 4.
As for the logic attributed to the learned trial judge by the appellant, again, in our view the appellant's submissions do not fairly represent the learned trial judge's reasoning. His Honour did not reason from the possibility of injury to the cerebellum beyond the right tonsil (as revealed by the 2014 MRI and the 2015 MRI) that those possible injuries therefore caused the respondent's Developmental and Cognitive Impairments.
As in the case of ground 2, the appellant's submission suffers from a piecemeal analysis of the evidence, which is to be contrasted with the approach (taken by the learned trial judge) of arriving at an inference based on 'the united force of all of the evidence together'.[340]
Indeed, we would also note that there is a significant difference between the reasoning and logic posited at [88] of the appellant's submissions and the short-form logic posited at [89] of those submissions (reproduced at [409] above). Unlike the conclusion at [89] ('Therefore X caused Y'), [88] of the appellant's submissions suggests a more modest conclusion (namely that the possibility of further damage 'is relevant to inferring that the [respondent's] Birth Injuries caused his Developmental and Cognitive Impairments').
This last proposition (namely that the possibility of more extensive damage capable of causing neurological and developmental impairments is 'relevant to inferring' causation) is, as a step in the reasoning process, entirely consistent with the authorities discussed above (see especially at [279] above).
Of course, such a possibility, on its own, would not be a sufficient basis to draw an inference of causation. Nevertheless it is admissible [i.e. relevant] and 'must be weighed in the balance with other factors, when determining whether or not, on the balance of probabilities, an inference of causation in a specific case could or should be drawn'.[341]
Ground 5 is not made out.

[307]

Ground 6 contends that the learned trial judge erred in law in finding that it was 'quite possible' that the plaintiff sustained a global microscopic brain injury caused by a breach of duty of the appellant.
The ground, again, alleges an error of law. Insofar as it alleges an error of law, the error is said to be the same erroneous reasoning the appellant described in its submissions in support of ground 5. Indeed paragraphs [96] and [97] of the appellant's submissions are essentially identical to paragraphs [88] and [89] (reproduced at [409] above) save that the reference to 'damage beyond the right cerebellar' is replaced with reference to 'global microscopic brain injury'.
Our conclusions in relation to those submissions are the same as set out in relation to ground 5. Indeed, there is a certain irony in the appellant's submission that the learned trial judge made precisely the same error in relation to two separate potential mechanisms of injury - namely in reasoning 'it is possible that X exists. X is capable of causing Y. Y exists. Therefore, X caused Y.'
The repetition of that submission in relation to both 'damage beyond the right cerebellar tonsil' and 'a global microscopic brain injury' (i.e. each of them is X), rather demonstrates that his Honour did not follow that logic in relation to either of them. It points up the piecemeal reading of the Primary reasons, which is not justified by those reasons as a whole.
While ground 6, strictly, only alleges an error of law, the appellant also developed submissions to the effect that the finding of fact (as to the possibility that the respondent suffered a global microscopic injury) was not open on the evidence as a matter of fact.[342]
In this regard, the appellant submitted that the finding was based solely on the evidence of Dr Keenan. Assuming, for present purposes, that to be the case, that does not necessarily reveal error on the part of the learned trial judge. His Honour was entitled to accept Dr Keenan's evidence in preference to Professor Ditchfield in that regard. And that is indeed, what his Honour did in the finding set out at [226] above.
His Honour did not, as the appellant submitted, ignore Professor Ditchfield's evidence. Indeed, his Honour referred to Professor Ditchfield's evidence, and concluded that Dr Keenan's clinical experience was different to Professor Ditchfield's in this regard and that Dr Keenan 'had regularly seen instances in which a child with a clinical syndrome similar to [the respondent] had shown global microscopic brain injury on more sophisticated imaging than that carried out in this case'.
Significantly, in this context, Dr Keenan's evidence was not that he could visualise a global microscopic injury on the MRI scans. His evidence was that it could not be observed on any of the scans.[343] The issue was, therefore, not one of radiological interpretation, as implied by the appellant's submission that 'the opinion of all of Ditchfield, Hunt, Nguyen, Shipman and Mason was the MRI scans did not show it'.[344]
On the contrary, Dr Keenan's evidence on this issue was based on the 'the setting of the clinical syndrome and with a grossly abnormal ultrasound' and 'many years of experience where we have very good evidence that in fact there has been neurologic deficits which we can't see'.[345]
This points to another aspect of the evidence as to the possibility of a global microscopic injury. It was not, as the appellant submits, solely based on the evidence of Dr Keenan. In that regard, as the learned trial judge expressly said, it served as an explanation for the evidence given by all of the expert witnesses (see [372] above) that not all injury to the brain will show up on [346] imaging.346 His Honour also referred to other explanations, such as damage to pathways in the brain that do not show up as struct[347]l damage.347
This is the context in which the finding as to the potential for a global microscopic injury is to be understood: the context of the entirety of the evidence and circumstances that are relevant to an inference as to the issue as to causation.
The learned trial judge was not in error in making that finding.
Ground 6 is not made out.

[391]

There a number of difficulties with this approach, as a suggested plausible alternative hypothesis for the respondent's Developmental and Cognitive Impairments (indeed, as the hypothesis suggests, they were not 'impairments' at all).
First, the approach could only be applied to each and every developmental symptom in a piecemeal fashion. That is because there were a very large number of functions or abilities that were assessed: including general intellectual functioning, language skills, literacy, numeracy, processing speed, visuo-motor integration and visual search, visual tracking, perceptual reasoning, working memory, attention, executive functioning and social cognition. In each of these different areas, the assessment of the respondent's percentile was different (e.g. 2nd percentile, 4th percentile, 3rd to 8th percentile etc).
It might be possible for the Court to calculate what each percentile means, in terms of the number of children in Australia above or below the respondent in relation to each respective ability. It might even be possible (with some hesitation) for a lay person to draw an inference that a particular result, in isolation, is more or less likely to be the result of a brain pathology. For example, a result in the 75th percentile (i.e. the top 25%) on one particular score alone might provide a very poor basis for inferring the existence of a brain pathology.
It is, however, altogether a different matter to be able, as a matter of logic, to attempt to analyse the combined effect of all of the respondent's limitations and draw the inference that the respondent may just be an ordinary 'below average' child, without the aid of expert evidence. That is not an exercise that can be undertaken by the Court without expert evidence.
This points up the second difficulty with concluding, as a matter of logic, that the respondent is 'just not very good at' some things.
In the present case, the inference which the learned trial judge ultimately drew as to factual causation - which inference the appellant challenges - was an inference based on facts (including possibilities) supported by the expert evidence. While some of the experts (such as Professor Ditchfield and Professor Hunt) were not prepared to draw that inference, others (such as Dr Keenan and Dr Tracy) were prepared to do so. No expert, however, ultimately denied the possibility of a causal connection, as a matter of medical science.
In such a case, as the authorities make clear, other circumstances may unite to warrant a conclusion that what the medical evidence established as a possible cause was the probable cause.
The appellant's position in relation to ground 21, however, is not that common sense permits the drawing of an inference from all of the circumstances that is open on the expert evidence. On this ground the appellant invites the Court to apply what the appellant submits is a common sense (or logical) view despite, and indeed contrary to, the expert evidence.
The learned trial judge relied upon the expert evidence before him to conclude that the respondent is not just an ordinary child at the lower end of the developmental spectrum. His Honour did not err in doing so.
Ground 21 is not made out.

[394]

As is apparent from the Primary reasons, the learned trial judge took into account the fact that there was no plausible inference competing with the inference that the respondent's Birth Injuries caused or materially contributed to Cooper's Developmental and Cognitive Impairments.[433]
We would make the following points in relation to this ground and the submissions in support of it.
First, there is no suggestion, either in the passage set out in [571] above, or in the Primary reasons as a whole, that his Honour was suggesting any onus 'on a defendant' to establish or suggest an alternative clause. His Honour correctly recognised, pursuant to s 5D of the Civil Liability Act, that the onus was on the respondent to prove, on the balance of probabilities, any fact relevant to the issue o[434]ausation.434 The appellant's submission that the passage set out in [571] above is 'inconsistent with s&#1[435]5D' must be rejected.435
Secondly, it perhaps goes a little far, to describe the passage set out in [571] above as articulating 'a principle of law'.
Rather, the relevance of the absence of a plausible inference competing with an inference of causation to the question whether such an inference should be drawn, is simply a description of the 'ordinary powers of human reason in the light of human experience'.[436]
As Evatt J observed more than 80 years ago, it is in the nature of an ordered process of logical thought that, in determining whether an inference should be drawn from all of the relevant facts and circumstances, regard must be had to every hypothesis which can compete with that inference.[437] The existence of competing hypotheses or inferences (and the strength of them) will affect whether, applying logic and common sense, the proposed inference should be drawn.
If there is a paucity, in number or quality, of possible explanations for a certain event, it is, as a matter of common sense, easier to draw the inference that a particular explanation is the only rational explanation (or the most likely explanation).[438] In the absence of any plausible alternative explanation, the particular explanation may be inferred with even greater confidence.
Leaving aside the matter dealt with in ground 21 above, the only possible alternative cause explored in the evidence at trial in the present case was that the respondent had attention deficit hyperactivity disorder (ADHD). The learned trial judge rejected ADHD as a 'plausible alternative hypothesis',[439] a finding not challenged in the appeal.
There was therefore nothing erroneous in the learned trial judge taking into account the fact that there was no other plausible explanation revealed by the evidence that competed with the inference that the respondent's Developmental and Cognitive Impairments were caused by the appellant's fault. To the contrary, in our view the absence of any other identified cause for those impairments was a circumstance of some significance in determining whether the ultimate inference of causation should be drawn.
His Honour, having thoroughly reviewed all of the evidence, was left with only one plausible inference as to the cause of the respondent's Developmental and Cognitive Impairments, namely an injury sustained in the course of his difficult and prolonged birth.
Of course, as the onus was on the respondent, his Honour was not obliged to conclude that that inference should be drawn.[440] Nevertheless, his Honour did draw the inference, and it was open for him to do so in light of all of the facts and circumstances. The absence of any other plausible explanation for the respondent's Developmental and Cognitive Impairments was simply one of the many circumstances.
Ground 20 is not made out.
The grounds dealt with above (grounds 1 to 16 and grounds 20 and 21) comprise all of the grounds of appeal relevant to the learned trial judge's finding of factual causation pursuant to s 5C(1)(a) of the Civil Liability Act; namely that the appellant's fault was a necessary condition of the occurrence of the respondent's Birth Injuries and his Developmental and Cognitive Impairments.
None of those grounds having been established, the appellant's challenge to the finding of factual causation must fail.

[402]

The appellant contends that the learned trial judge erred in law in applying the notion of 'material contribution' to harm as an established principle giving rise to an 'appropriate case' within the meaning of s 5C(2). As part of that contention, the appellant submits that his Honour gave no reason for his conclusion that the present case was an appropriate one for the application of s 5C(2).[442]
We accept the appellant's submissions in this regard. In our respectful view, the learned trial judge's analysis of s 5C(2), and in particular his Honour's approach of the notion of 'material contribution' in that context, confused the important difference between s 5C(1)(a) and s 5C(2). Whether, and in what way, 'material contribution' might have a role to play in the application of s 5C has yet to be finally determined. Nevertheless, it does not operate in the manner that the learned trial judge appears to have applied it in Primary reasons [942].
To explain why this is so it is necessary both to address the different ways in which 'material contribution' has been used in the past and to address the statutory purpose of s 5C(2).
First, dealing with 'material contribution', as the High Court recognised in Strong v Woolworths Ltd,[443] the expression 'material contribution' has come to be used in a number of different ways in the context of causation in tort.
The way in which 'material contribution' is more commonly understood in this State following the decision in Western Australia v Watson,[444] is as a synonym for the principle that a plaintiff need only prove that the defendant's negligence is 'a' cause (and not 'the' cause) of his or her damage. It is often said, for example, that the plaintiff must establish that the defendant's negligence 'caused or materially contributed to' his or her loss. In this sense, the phrase is simply a recognition that the defendant's fault need only be one cause (or 'a cause') of the plaintiff's harm. The contribution of other causes does not negate the causal connection if the defendant's negligent act is 'a cause'.
The majority of the High Court explained this in Hunt & Hunt Lawyers v Mitchell Morgan Nominees Pty Ltd as follows:[445]

[406]

'Material contribution' in this sense is applied in a context where the 'but for' test cannot be applied. In Bonnington Castings Ltd v Wardlaw,[449] this was because it could not be said that without ('but for') the 'quota of silica dust' contributed to by the negligence of the appellant, Mr Wardlow would not have developed the disease. And that was, in turn, because it was the accumulated gradual exposure to silica dust that had caused the disease, and no single part of that accumulated exposure could meet a 'but for' test.
The difference in the use of the word 'material contribution' in that case might be illustrated by reference to the notion of 'a necessary condition' in s 5C(1)(a) of the Civil Liability Act. In Bonnington Castings Ltd v Wardlaw, the relevant 'necessary condition' for the respondent's pneumoconiosis was the undifferentiated accumulation of exposure to silica, not any particular portion of it (in particular, because it was impossible to 'separate out' the role of any one quota of the silica dust from another). In that case, therefore, while the 'quota of silica dust' contributed to by the negligence of the appellant could not itself be said to be a necessary condition of Mr Wardlaw's disease, it could be said to have 'materially contributed' to a necessary condition (the accumulated exposure). In such a case, notwithstanding that there was an 'evidential gap', the particular circumstances in Bonnington v Wardlaw were such that the 'evidential gap' could be jumped.[450]
This is where s 5C(2) comes in.
As is apparent from the text of s 5C(2), it is concerned with an 'appropriate case' in which by reason of the particular circumstances fault 'cannot be established as a necessary condition'. The word 'cannot' is, in our view, significant in this context. Section 5C(2) is not concerned, in our view, with a case in which evidence 'does not' establish factual causation (in the sense that there could be evidence to support a finding of a necessary condition, but no such evidence is adduced). It is concerned, rather, with a case in which there 'cannot' be such evidence because of the nature of the case.[451]
This, in our view, provides assistance in giving content to what is intended by s 5C(2) to be 'an appropriate case'. While the equivalent provision in New South Wales (s 5D(2) of the Civil Liability Act 2002 (NSW)) refers to 'an exceptional case', the nature for that inquiry is reflected in the High Court's decision in Adeels Palace Pty Ltd v Moubarak:[452]

[410]

Fairchild v Glenhaven Funeral Services Ltd[455] (and other cases such as Bonnington v Wardlaw and McGhee v National Coal Board)[456] concern circumstances where an 'evidential gap' existed because it was impossible to determine which of a number of multiple sufficient causes gave rise to an indivisible disease. In such a case, the 'evidential gap' exists not because the evidence called by the plaintiff does establish a causal link but, rather, because no such evidence exists.
That s 5C(2) was intended to deal with unusual cases such as this is confirmed by the recommendations of the report to the federal Minister for Revenue and Assistant Treasurer prepared by a Panel chaired by the Hon David Ipp entitled Review of the Law of Negligence Final Report dated September 2002 (the Ipp Report).[457] The word 'appropriate' appears to have been taken from the Ipp Report,[458] and arose in the context of the Committee's discussion of the difficulties created by cases such as Bonnington v Wardlaw and Fairchild.[459]
The metes and bounds of what is an 'appropriate case' for the purposes of s 5C(2) of the Civil Liability Act remain to be determined. It is clear, however, that s 5C(2) does not apply merely because a plaintiff is only able to prove that the defendant's fault may have been a cause of the harm.[460] A case is not an 'appropriate case' merely because the plaintiff has failed to discharge his or her onus under s 5C(1)(a). Something more is required.
In truth, in our view, s 5C(2) had no role to play in the present case. The respondent either established factual causation under s 5C(1)(a) or he did not. If he failed to do so, there was nothing about the circumstances of the case, based on established principles, to invoke s 5C(2).
In particular, no analogy could be drawn between the present case and cases such as Bonnington v Wardlaw, Fairchild and McGhee. The learned trial judge recognised as much in Primary reasons [720] (see [592] above). In those circumstances the notion of 'material contribution' in its more nuanced sense discussed in [602] to [604] above had no role to play. To be fair the learned trial judge, it is not entirely clear in what sense his Honour was invoking the concept of 'material contribution' at Primary reasons [942]. Despite the opening words of that paragraph, his Honour may have been doing no more than using 'material contribution' in its more commonly used sense discussed at [597] to [599] above. If that be the case, however, the finding adds nothing to the finding already made in relation to s 5C(1)(a).
For these reasons we would uphold ground 17. Nevertheless for the reasons we have explained, success on ground 17 does not have the consequence that the appeal should be allowed.

[431]

(a) the case was a difficult one;

(b) it was difficult to predict the result of the trial;

(c) the defendant believed that it had reasonable prospects of success; and

(d) it was reasonable for the defendant to take the view that it did at the time to reject the Rule 42A Offer.

However, applying the principles set out above ([44]) none of these findings are sufficient to warrant the exercise of the discretion to displace the default position.

The findings in [49] are reflective of an ordinary case in the District Court proceeding to trial. If the defendant did not have evidence, including expert evidence, which it believed, on advice, would be preferred at trial, common sense suggests that it would have settled the action before that point in the life of the action. In this modern age of court sanctioned mediation and case management, a personal injuries case should not proceed to trial unless there is a significant conflict in the evidence or the applicable legal principles. If the mere fact that a defendant had evidence, including expert evidence, which it believed, on advice, would be preferred at trial is a sufficient basis for the court to 'otherwise order' pursuant to DCR r 42A(4), then the rule would cease to have any meaningful effect. Hence the principles set out above [44] have the practical effect that the defendant must point to more than a mere conflict in the evidence in order to move the court to order otherwise.

The defendant did not submit that there was any factor in the circumstances in which the Rule 42A Offer was made that would justify the exercise of the discretion to order otherwise. For example, it was not submitted that, at the time of delivery of the Rule 42A Offer, the nature of the plaintiff's case was not clear. Nor was it submitted that the plaintiff only succeeded upon a case which emerged from subsequent amendments to the pleadings or that the extent of the loss and damage only emerged from material subsequently disclosed. There is no suggestion in the materials before the court that the defendant did not have an informed opportunity to assess the chances of doing better than the offer.

The defendant has not demonstrated any reason sufficient to justify the exercise of the discretion to 'otherwise order' in DCR r 42A(4). I decline to exercise the discretion with the effect that the plaintiff's costs in respect of the claim from the date on which the offer was made, 6 April 2017, are to be taxed as between a law practice and its client. This includes any reserved costs.

EAST METROPOLITAN HEALTH SERVICE -v- ELLIS (by his next friend CHRISTOPHER GRAHAM ELLIS) [2020] WASCA 147 (10 September 2020)

At a glance

Court

Decision date

Before

Source

Judgment (619 paragraphs)

Significance of the diagnosis of hypoxic ischaemic encephalopathy

The profile of the respondent's developmental issues

Other potential causes of the Developmental and Cognitive Impairments

Finding as to extent of haemorrhagic contusion was not indispensable

Whether there was a rational basis for preferring one view over the other

The learned trial judge's approach in this case

Factual findings made by the learned trial judge

Legislation Cited (2)

Cases Cited (27)