Challenges on appeal
30 The challenge to the findings of the primary judge had, in effect, two limbs. The first was that his Honour should have rejected or substantially discounted the value of the medical reports tendered on behalf of the Respondent, because of discrepant histories recorded by those doctors. The second basis of challenge relied upon apparent inconsistencies in certain findings made by the trial judge, set out above.
31 The first basis of challenge was directed to establishing that the trial judge should have discounted the views of those experts for the Respondent who did not provide a statement of the history of the injury consistent with the evidence given by the Appellant at trial, or as recounted by Dr Adler. However, this line of challenge ran into two difficulties. The primary difficulty is that the opinion of an expert may be discounted on the basis of substantially incorrect factual assumptions, but those factual assumptions must be assessed against the findings made by the trial judge: Makita (Australia) Pty Ltd v Sprowles (2001) 52 NSWLR 705 at [64]-[65] (Heydon JA). As already noted, the findings of the trial judge did not accord with the history recounted by Dr Adler and, to the extent that they were favourable to the Appellant, they were limited to an acceptance of regular severe migraines and continuing pain in the right arm. As noted above, it appears that his Honour intended to qualify the seriousness of these findings to some extent.
32 Further, it cannot be said that Drs Matheson, Slezak and Hughes did not consider these claims. For example, the history set out by Dr Matheson in his report of 5 December 2001 demonstrated that he considered these complaints but did not consider that the nature of the injury was consistent with production of a disc lesion, or that the disc lesion produced the arm pain complained of. He did not reject the symptoms described, but attributed them to "muscle strain" rather than the neck injury, which he treated as the C4/5 disc lesion. Nor did Dr Slezak deny the existence of the pain in the upper arm, but rather described it as a "syndrome" for which no organic basis could be identified. This was consistent with the findings made by his Honour. Dr Hughes, in contrast to Dr Matheson, was of the view that she would have difficulty working as a hairdresser: his opinion was supportive of the Respondent's case, but only in so far as he rejected any causal connection between the incident at work and the neck condition, which he saw as a degenerative condition.
33 On the other hand, it could well be said that the factual history upon which Dr Adler relied was, to a significant extent, not accepted by his Honour. Accordingly, an analysis of the underlying assumptions of the various medical practitioners provides no assistance to the Appellant in challenging the findings made by his Honour.
34 The second limb of the challenge is of greater concern. As noted above, his Honour accepted that the Appellant suffered from a "traction injury" caused during her employment with the Respondent. The term "traction injury" is not explained in the judgment, but appears to reflect the language adopted by Dr Adler, who spoke of a "traction nerve root injury". The Respondent suggested it might also be reflective of the language of Dr Darveniza, who spoke of the Appellant suffering a "stretching or wrenching injury", leaving her with "chronic neck pain and migrainous headaches twice per week, sensory loss in the right upper limb in an non-anatomical distribution and restricted use of the right upper limb".
35 The view that she had suffered a traction nerve root injury was not inconsistent with his Honour's rejection of the protrusion at disc C4/5 as the cause of her problems. However, if his Honour were intending to accept the existence of a traction nerve root injury, which is presumably responsible for her continuing migraines and right arm pain, there was significant evidence supporting the view that she would not be able to work as a hairdresser. Accordingly, there would then be a real issue as to whether his Honour's assessment of 15% of a most serious case was not below a reasonable range for such an assessment.
36 With this problem in mind, it is necessary to return to the Respondent's experts to consider the relevance of their evidence to such a finding. As already noted, Dr Lloyd Hughes is, in the relevant sense, supportive of the Appellant's case. He thought that "there is probably some nerve root irritation from the degenerative disc lesion" and agreed she would have difficulties in working as a hairdresser.
37 Dr Slezak found that there was "no organic basis" for the alleged "sensory impairment" affecting the right arm and right side of the neck. He did not comment on the migraines. If his Honour identified an organic cause in the sense of a traumatic nerve root injury, there must be doubts as to whether the evidence of Dr Slezak assists the Respondent significantly.
38 Similarly, Dr Matheson is of the view that there simply was no relevant nerve root pathology. Again, if his Honour found that there was such a condition, Dr Matheson is of no direct assistance to the Respondent.