But the view expressed in that case and in the cases in this Tribunal that have followed it, is that potential error, as opposed to actual error, provides a sufficient basis to make a referral to an IMA, with a view to either establishing or allaying concerns about that perceived error.

For example, in Martin v Department for Communities and Social Inclusion[23] the Tribunal referred a WPI assessment to an IMA out of concern that the assessing doctor's findings regarding radiculopathy might have reflected transitory acute presentation that required further investigation.

In March v Return to Work SA (Northland Caravans)[24] it referred a WPI assessment to an IMA having found that the assessing doctor based his assessment at least in part on assumed facts that in the Tribunal's opinion may not have been credible.

In Adom v Return to Work SA[25] it referred a WPI to an IMA out of concern that the worker's loss of sensation in his face, found by the assessor to be limited to one side, may, in fact be bilateral.

In Zwarts v Broadspectrum (Australia) Pty Ltd[26] it referred a WPI assessment to an IMA out of concern that the existence of a pre‑existing impairment had not been excluded.

As a Full Bench we endorse this approach, and unless or until a higher court holds otherwise, a serious concern of potential error in a WPI assessment, as opposed to a finding of actual error, ought be seen as a sufficient basis to contemplate referral to an IMA.[27]

1. In this case, the assessment of Dr Flapper, in respect of the atypical facial pain injury, is occasioned by sufficient doubt and apparent error that I would not be prepared to give effect to it without further evidence.
2. I have no difficulty in finding that Ch 1.11 of the IAG permits an assessment of trigeminal nerve injury to be made in an appropriate case.
3. Ch 1.11 makes it clear that pain per se will not be the subject of a separate assessment. However, where pain accompanies an impairment such as within Chapter 5, it may be factored in.
4. The necessary first step is to identify whether the applicant has an impairment within Ch 5.14. If the impairment is accompanied by pain, it may be factored in. However, the approach of Dr Flapper to the task of assessment seems to be circular. This is highlighted by the following excerpt from his report:

Ms Knox has been diagnosed with myofascial pain affecting her face. The face receives its sensory innervation from the trigeminal nerve and therefore any facial pain is going to be related to the trigeminal nerve.[28]

1. I have previously quoted the cross-examination of Dr Flapper where he is unable to comment on whether the pain is due to nerve abnormality or an abnormal response to the nerve. The former would be in keeping with a nerve injury which could properly be the subject of an impairment assessment; the latter suggests something more in the nature of a pain syndrome which would not be assessable by virtue of Ch 1.11 of the IAG.
2. Further, the allocation of impairment does not appear to be in accordance with the IAG. Dr Flapper states: "I have allocated 5% whole person impairment for each side and a total of 10% whole person impairment for her pain."[29] Dr Flapper goes on to explain that he had "allocated a total of 10% for her pain. Given the pain is symmetrical, I have allocated half to each side."[30]
3. Contrary to the requirements of Ch 5.14 of the IAG, in assessing trigeminal nerve impairment, Dr Flapper did not assess each side separately. Rather, he either assessed a figure and duplicated it for each side, or assessed a total and halved it. Either way, this is not consistent with the evidence of the applicant, that the right side of her face is much worse than the left, nor in accordance with the IAG. For this reason also, the assessment of Dr Flapper is indicative of error.
4. Dr Flapper suggests that the opinion of a neurologist would be required to determine the answer to this question. As the answer appears to be a precondition to a valid Ch 5.4 impairment assessment, I would benefit from an IMA by a neurologist.
5. In the first instance, I propose obtaining a neurological opinion on the question of trigeminal nerve impairment only. What may flow from that assessment would need to be the subject of further submissions.

1. I am not satisfied that the assessment of Dr Flapper of atypical facial pain impairment is in accordance with the IAG.
2. I propose to refer that issue to an IMA.
3. I will hear the parties as to the appropriate IMA and the terms of reference relating to same.

[1] See Smout v RTWCSA [2025] SAET 36 and the discussion in Van Loggem v RTWCSA [2025] SAET 47

[17] [2021] SASCFC 44.

[19] [2016] SAET 76.

[21] [2018] SAET 27.

[22] [2025] SAET 24

[23] [2018] SAET 57

[24] [2018] SAET 86

[25] [2019] SAET 70

[26] [2021] SAET 148