Department of Defence v Speed, T.A

[1993] FCA 186

Re: DEPARTMENT OF DEFENCE
And: TRUDIE ANNE SPEED
No. SG74 of 1992
FED No. 186
Number of pages - 21
Administrative Law

COURT

IN THE FEDERAL COURT OF AUSTRALIA

SOUTH AUSTRALIA DISTRICT REGISTRY
GENERAL DIVISION
Cooper J(1)

CATCHWORDS

Administrative Law - appeal from Administrative Appeals Tribunal - claim for compensation in respect of an incapacity resulting from a medical condition - whether as a matter of probability that her employment as a nursing sister with the Army was a contributing factor to the contraction of the disease - whether an error of law in Tribunal's reasoning - whether a possible cause may be elevated to a probable cause - whether findings open to the Tribunal on the evidence - common sense principles - whether degree of exposure to the trigger virus appreciably higher due to her duties of employment than the community at large - unidentified trigger virus - encephalomyelitis - incubation periods.

Administrative Appeals Tribunal Act 1975 Section 44(1)

Compensation (Commonwealth Government Employees) Act 1971 section 29(1)(b)

McAuliffe v. Department of Social Security (1991) 13 AAR 462

Dorman v. Riordan (1990) 24 FCR 564

Collins v. Minister for Immigration (1981) 36 ALR 598

Sullivan v. Department of Transport (1978) 20 ALR 330

Wilcox v. Commissioner of Taxation (1988) 79 ALR 263

Lennell v. Repatriation Commission (1982) 4 ALN N29

Repatriation Commission v. Bushell 91991) 13 AAR 176

Bisley Investments Corporation v. Australian Broadcasting Tribunal (1982) 59 FLR 132

Opitz v. Repatriation Commissioner (1991) 29 FCR 50

Tubemakers of Australia Ltd. v. Fernandez (1976) 10 ALR 303

Dahl v. Grice (1981) VR 513

Nesterczuk v. Mortimore (1965) 115 CLR 140

EMI (Australia) Ltd. v. Bes (1970) 2 NSWR 238

Treloar v. Australian Telecommunications Commission (1990) 26 FCR 316

Federal Broom Co. Pty. Ltd. v. Semlitch (1964) 110 CLR 626

HEARING

ADELAIDE, 22 March 1993

#DATE 30:3:1993

Counsel for the Applicant: Mr Cameron

Solicitors for the Applicant: Australian Government Solicitor

Respondent in Person: Ms T.A. Speed

ORDER

THE COURT ORDERS:

That the application be dismissed.

Note: Settlement and entry of orders is dealt with in Order 36 of the Federal Court Rules.

JUDGE1

COOPER J This is an appeal under section 44(1) of the Administrative Appeals Tribunal Act 1975 by the Department of Defence from a decision of the Administrative Appeals Tribunal ("the Tribunal") dated 15 September, 1992 whereby the Tribunal set aside the decision of the delegate of the Commissioner for Safety, Rehabilitation and Compensation of Commonwealth Employees rejecting the respondent's claim for compensation in respect of incapacity resulting from a medical condition, namely, encephalomyelitis. In lieu of the decision of the delegate, the Tribunal determined that Ms. Speed was entitled to be compensated on the basis of a partial incapacity resulting from her work-related condition of encephalomyelitis. The Tribunal ordered the applicant to pay to the respondent the costs of the application and the proceedings before the Tribunal.

1. The applicant appeals from the whole of the decision of the Tribunal and seeks an order that the decision of the Tribunal of 15 September, 1992 be set aside.

2. In 1984 the respondent was a qualified nurse. On 24 September, 1984 she enlisted in the Army as a nursing Lieutenant. In October, 1985 she was transferred to the 3 Camp Hospital at Puckapunyal as a nursing officer in charge of wards. The nursing officers were primarily responsible for the supervision of ward patients and the reception of soldiers seeking medical attention. The hospital was under the command of Dr. A.B. De Sousa.

3. The Tribunal found the following facts relevant to this application :-
   

(a) In the period immediately prior to the respondent taking leave on 8 December, 1986 the respondent in the discharge of her duties attended on patients suffering from viral infections;

(b) The respondent took annual leave between 8 and 21 December, 1986;

(c) The respondent spent the first five to six days of the holidays in Sydney visiting friends;

(d) The respondent then drove to Puckapunyal, stayed overnight and, in the company of a friend continued her journey on to the family home at Mildura;

(e) The respondent arrived at Mildura on 14 December, 1986;

(f) Within a day or so of her arrival at Mildura certain physical and behavioural changes in her were observed; she was constantly tired and this was accompanied by uncharacteristic irritability;

(g) The respondent returned to Puckapunyal on 21 December, 1986 and recommenced her duties the next day in terms of the new roster system ie. seven days on, two days off;

(h) On 25 December, 1986 the respondent developed significant nausea and headaches, suggesting an acute viral illness;

(i) The respondent's condition worsened and she was admitted to the hospital on 28 December, 1986;

(j) On 2 January, 1987 the respondent was transferred by ambulance to Repatriation General Hospital at Heidelberg and was there diagnosed :-

"acute demyelination syndrome - probably post viral encephalomyelitis"

(k) The respondent, on the medical evidence which the Tribunal accepted, in fact did suffer post viral encephalomyelitis.

1. Dr. Stanley, a consultant physician, in a report tendered in evidence, expressed the opinion :-
   

"'In my view it would seem that the most likely diagnosis is a brain stem encephalitis - post-infective in nature, that is, that the encephalitis occurred as an allergic or hypersensitive response to a preceding, often trivial infection'"

The Tribunal in its reasons after setting out the opinion of Dr. Stanley, stated :-

"15. .... It therefore becomes apparent that there are two stages involved; first the contraction of the viral infection and secondly the response to that condition which leads to the onset of the encephalomyelitis. One cannot contract the second without first experiencing the viral infection. Expressed in another form, the viral infection is a trigger to the final condition suffered by the applicant and thus it becomes necessary to consider whether that trigger could be perceived as a cause arising out of her employment as a nursing sister with the Army. It is noted that the type of viral infection contracted by the applicant was never identified. .....

16. The Tribunal now turns to a consideration of the medical evidence. In so doing the Tribunal records that all doctors giving evidence accepted the two stage process outlined above".

1. The Tribunal then reviewed the medical evidence before the Tribunal. As it is alleged that the Tribunal's review was in error or flawed, I set out in full the Tribunal's observations on the point :-
   

"17. The evidence of Dr. De Sousa, the former officer in charge of the Hospital at Puckapunyal, not only confirmed the events of 25 December to 2 January 1987 but also that the applicant had attended sick people some of whom had viral illnesses in the pre-holiday period. In a medical report dated 12 October 1990 he opined that the applicant had contracted the viral illness whilst working as a nursing sister. Under cross-examination he appeared to accept that there was no foundation for such a conclusion.

18. Dr. H. Waddy, a consultant neurologist, saw the applicant on 28 May 1991 and prepared a report bearing as its date 25 July 1991. In that report Dr. Waddy accepted the previously diagnosed medical condition and then attempted to determine when the applicant contracted the virus which, in turn, triggered the encephalomyelitis. The doctor referred to the likely incubation and response periods for the two stages and reached the following conclusion - 'In essence then it seems virtually impossible to determine at this late stage when any pre-existing infection occurred. The viruses mentioned have variable incubation periods and I don't think any further steps can be taken to elucidate this any further. It would seem more likely however that it predated her holiday period'. In forming that opinion it seems that the doctor placed some reliance on the mistaken view that the holiday period extended from 14 to 22 December and that the applicant was extremely run down from working long hours at the Hospital. In any event, it seems that the doctor's opinion would have remained the same irrespective of those factors.

19. In her oral evidence, Dr. Waddy expanded her thoughts on the issue of the incubation and response periods. Whilst agreeing that those periods are variable she expressed the view that the range of seven to 21 days was representative of the time normally taken to advance from exposure to the virus to getting the virus, ie. the incubation period. Following that event there is the allergic response that results in the encephalomyelitis. In Dr. Waddy's opinion that response usually takes about three weeks or even longer. On the basis of those parameters, and the assumption that the encephalomyelitis had developed on or just after 25 December, the doctor concluded that the exposure to the virus occurred prior to 8 December, ie. prior to the taking of the two weeks holiday.

20. The medical views expressed by Professor Burns and Dr. Heddle are in the main similar to those indicated by Dr. Waddy. It is their conclusions, particularly as to timing, that are of significance. Because of the scope for variation in the contracting periods, neither of them was in a position to determine commencement dates for either the viral infection or the encephalomyelitis. In the words of Professor Burns, 'she might well have contracted the virus in the course of her work or in her leisure time - one cannot say'. In the course of giving his evidence he proffered an incubation period of anywhere between three and twenty days for the virus and a response delay of three to fourteen days or maybe longer for the encephalomyelitis. Dr. Heddle stated his uncertainty in the following terms - 'It appears to me from detailed reading of the material presented, that it is impossible to either confirm or refute the possibility that the viral illness may have been acquired in the course of Army duties at Puckapunyal...'. Incubation and response periods of twenty four hours to twenty days and four to fourteen days respectively were suggested by Dr. Heddle".

1. The Tribunal concluded on the whole of the evidence and the submissions that the respondent contracted the disease known as encephalomyelitis, that her employment by the Commonwealth was a contributing factor and that a partial incapacity for work had resulted. In reaching this conclusion the Tribunal said :-
   

"25. In the present matter, the applicant's submission has two limbs ie. that the viral infection was encountered at the Hospital while attending to the needs of patients and that, because of the heavy work load existing prior to 8 December, she was more susceptible to that disease. Furthermore she contended that her then run down condition was worsened by the non taking of her full annual leave entitlement. The leave records of the applicant formed part of the T documents before the Tribunal and it is noted that during the total period of her employment - a period just in excess of twenty six months - annual leave and sick days taken totalled thirty days. The sick days were taken to clear an entitlement and were in no way related to any sickness. The evidence before the Tribunal does not permit a finding that the applicant was either physically or mentally 'run down' at or about 8 December 1988 and accordingly that part of her submission is rejected. However, the time parameters set down by all the medical witnesses indicate that the contraction of the disease prior to the taking of holidays was a distinct possibility. The fine line decision required of this Tribunal is whether the circumstances of her employment raise such a possibility to a probability. On the issue of timing the Tribunal after examining all the medical evidence finds that the symptoms of the viral infection appeared on or about 17 December whereas the symptoms indicating the arrival of the encephalomyelitis became apparent on or about 25 December.

26. It will be recalled that during the period immediately before the taking of holidays, the applicant was carrying out the duties of a ward nurse at the Hospital and that in the course of those activities she was required to attend on patients suffering from viral infections. The adoption of 'common sense principles' has led the Tribunal to the conclusion that the degree of exposure occurring at that time was appreciably greater and for that reason it is our view that the possibility should be elevated to a probability. True it is that the contraction of the viral infection during the holiday period may be a possibility and yet, when one considers all of the circumstances, logic demands that contact and thus contraction occurred at Puckapunyal where the applicant was caring for the needs of patients suffering from viral infections. The Tribunal concludes that the applicant, pursuant to her contract of employment, was required to be in a particular place which exposed her to risks additional to those likely to be encountered in normal circumstances and that the exposure resulted in the contraction of her disease. In terms of the Treloar decision the degree of exposure suffered was greater than that to which the applicant would have been subjected to were it not for her employment and thus it follows that this 'state of affairs' qualifies as a 'contributing factor'. For these reasons the Tribunal is satisfied that her employment with the Army was a contributing factor to her medical condition. As the encephalomyelitis was triggered by the work related viral infection it is correct in our view to also regard that illness as being work related".

1. The applicant contends that the Tribunal in coming to the decision which it did made a number of errors of law. In summary form they are :-
   

(a) That the finding that the symptoms of viral infection appeared on 17 December, 1986 (without making any finding as to what those symptoms were) failed to adequately comply with the Tribunal's obligation to give reasons under section 43(2B) of the Administrative Appeals Act 1975 (see McAuliffe v. Department of Social Security (1991) 13 AAR 462 at 477; Dorman v. Riordan (1990) 24 FCR 564).

(b) There was no evidence to support a finding on the balance of probabilities as to the link between the virus and the employment (Collins v. Minister for Immigration (1981) 36 ALR 598 at 601).

(c) The Tribunal misapprehended the opinion of Professor Burns and should have given effect to his evidence that the most likely time that the viral illness was present in the respondent was some time between 11 and 22 December, 1986 when the respondent was on holiday. That the failure to do so constituted an error of law (Sullivan v. Department of Transport (1978) 20 ALR 330 at 350; Wilcox v. Commissioner of Taxation (1988) 79 ALR 263 at 276-277).

(d) The Tribunal made findings against the medical evidence and in circumstances where there was no other evidence to support those findings. In particular, it was submitted, logic did not demand a finding that contact with patients suffering viral illnesses in the course of her employment at Puckapunyal led to contraction of a virus which in turn triggered the encephalomyelitis.

1. In Lennell v. Repatriation Commission (1982) 4 ALN N29, Northrop and Sheppard JJ said :-
   

"A court exercising supervisory jurisdiction over an administrative tribunal ought not lightly interfere with its decisions even if the court feels that the tribunal's language may have a degree of looseness. Certainly it ought not to indulge in an exercise which overzealously picks the tribunal up in the way it has expressed itself. That is particularly so when it appears properly to have understood the legal principles which it is to apply".

1. This approach was cited with approval by the Full Court in Repatriation Commission v. Bushell (1991) 13 AAR 176 at 182-183.

2. When one considers the adequacy of the reasons given, it is necessary to determine that question by reference to a reading of the reasons as a whole remembering that what is required is "substantial compliance" (Bisley Investments Corporation v. Australian Broadcasting Tribunal (1982) 59 FLR 132 at 151-152; 155-156; Opitz v. Repatriation Commissioner (1991) 29 FCR 50 at 61).

3. In my opinion the reasoning of the Tribunal in finding that the symptoms of the viral infection appeared on or about 17 December, 1986 are adequate. The Tribunal found that within a day or so of returning home on 14 December, 1986 the respondent became constantly tired and uncharacteristically irritable. This placed the changes at about 17 December. The Tribunal then states that an examination of the medical evidence leads it to conclude that the symptoms of the viral infection appeared on or about 17 December, 1986. It is not incumbent on the Tribunal in my view to set out all the evidence on which it relies. It has identified the basis of its reasoning. Recourse to the evidence shows that the date of the 17th is supported by the evidence of the respondent's mother. Dr. Heddle regarded the symptoms (irritability) about 17 December, 1986 as consistent with and more probably the symptoms of the viral infection than the development of post-infectious encephalomyelitis (transcript pages 232-233). Professor Burns accepted the condition of being unusually tired and irritable as being symptoms consistent with the virus which triggered the encephalomyelitis (transcript pages 137-138). The other medical evidence is consistent with the opinions of Dr. Heddle and Professor Burns. The reasoning of the Tribunal is clear enough and it is supported by the evidence.

1. The Tribunal did not, in my view, misapprehend the evidence of Professor Burns. The evidence relied upon by the applicant is :-
   

"So that anywhere between three days prior to Christmas Day and anyway as far as back as 14 days is what you're saying is where the viral illness occurred. That that's the most likely?---Most likely. Exactly that's what I am saying. .....

MR. TROWSE: I wonder if you'd take me through the 14 day formula again, doctor?---Sure yes. Christmas Day we have signs appearing. Now, is that the end of the incubation period with regards to the second illness or is that the start of the - - - ?---No. The Christmas Day is the start of the secondary illness. It's the start?---Start of the secondary illness and therefore the most likely time which she would have contracted the virus would be 22 December which is three days before to the - or 14 days before that which would be 11 - yes 11 December. So somewhere between 11th and 22 December would be by far and away the most likely time that this viral illness was present".

1. This evidence has to be read with earlier evidence given by Professor Burns when he said :-
   

"Of course, the average viral illness that we get has an incubation period of somewhere between two and 14 days and then as I said earlier, the latent period from the onset of the viral illness to this disease is probably about 14 days or less and so it seems unlikely though not impossible that the viral illness was contracted early in December to have caused this illness".

1. The effect of Professor Burns' evidence is that the symptoms of encephalomyelitis started on Christmas Day (25 December, 1986), and in this he is agreed with by the other medical opinion, and, that the response time of this condition to develop from an exposure to the virus was a period of 3 - 14 days. However, that virus itself has an incubation period from the time of original contact with the virus which for the "average viral illness...(is) an incubation period of somewhere between two and 14 days". The two periods have to be added together to ascertain a possible date of first contact with the virus. When Professor Burns speaks of the time when "the viral illness occurred" or the "time which she would have contracted the virus" he is talking of the condition of the respondent at a time when she had a viral illness that time being after the expiration of the original incubation period of the virus. It is then the viral illness itself which triggers the response and second incubation period which ultimately leads to the secondary illness (encephalomyelitis). It is the second period of incubation which commenced between 11 and 22 December, 1986. Whether or not the first incubation period commenced between those dates depends upon the actual date within the range that the virus was present. With a primary incubation period of between two days and fourteen days for an average virus, the original contact date could be within or substantially outside that period.

2. The Tribunal in ascribing to Professor Burns evidence that the incubation period for the virus was between three and twenty days was referring to the following evidence given by him :-
   

"What's the shortest incubation - sorry, what virus would have the shortest incubation period?---You're talking about - not about post-infectious state, you're just talking about - - - I'm talking about the viral - - -?---When you contract the virus, or catch it, or when you develop the symptoms, it may be as short as a few days - two or three days. And depending again on what it is - with measles the incubation period there being 10 to 20 days?---Yes, measles and mumps are sort of longer. Some of the viruses that we all get are much shorter than - an incubation period much briefer than that".

1. The further statement by the Tribunal of the evidence of Professor Burns as being that there was a response delay of three to fourteen days or longer for the encephalomyelitis to develop is supported by the evidence set out earlier. The evidence of Professor Burns, as found by the Tribunal, is consistent with the evidence of Drs. Waddy and Heddle that there was a two stage nature to the process and that two periods, one of incubation and one of reaction, were involved in it. The reference by the Tribunal to an outer limit of twenty days in the evidence of Professor Burns does not detract from the Tribunal's understanding of his evidence. The variations between the medical experts was as to the length of these periods in ordinary circumstances, not as to the constituent elements involved in the process leading to the secondary disease.

2. The whole of the medical evidence established that the respondent was exposed to a virus because this was a necessary pre-condition to her contracting post-viral encephalomyelitis. The whole of the medical evidence was that the possibilities as to where she was exposed to and caught the virus were either that she contracted it at Puckapunyal (whether she was engaged in duties or on leisure time), or somewhere else when she was on holidays. The doctors disagreed as to the strength of the likelihood of the contact being made at a time when the respondent was in camp. The Tribunal recognised this when it said:-
   

"However, the time parameters set down by all the medical witnesses indicate that the contraction of the disease prior to the taking of holidays was a distinct possibility. The fine line decision required of this Tribunal is whether the circumstances of her employment raise such a possibility to a probability".

1. The Tribunal correctly directed itself that the respondent must show as a matter of probability that "any employment of the employee by the Commonwealth was a contributing factor to the contraction of the disease...whether or not the disease was contracted...in the course of that employment" (Section 29(1)(b) of the Compensation (Commonwealth Government Employees) Act 1971 ("the Act")) and that a mere possibility was not enough.

2. The Tribunal was not bound to accept the evidence of Professor Burns over the evidence of Drs. Waddy or Heddle and was entitled to look at the sequence of events and other evidence to determine whether or not a possible cause may be elevated to a probable cause (Tubemakers of Australia Ltd. v. Fernandez (1976) 10 ALR 303 at 310-312, 313). The correct approach to be taken by the Tribunal and its use of the medical evidence in situations similar to the present is set out in Dahl v. Grice (1981) VR 513 at 522 per Gobbo J with whom Young CJ and Kaye J agreed :-
   

"The review of the authorities leads me to reject the appellants' argument that in matters of bodily health, even outside common experience, it is incumbent on a plaintiff to prove the causal connection to the requisite degree of probability by evidence from the expert. It is plain that in such matters the courts have recognized that a possible cause may be elevated to a probable cause. There are a number of reasons why it is undesirable that the opinion as to causal connection be stated in terms of probabilities. In the first place, this is the role of the tribunal of fact and the ultimate task rests with the judge or jury, as the case may be. Secondly, it is inadmissible in the ordinary course for an expert to give evidence in a form that takes up the very ultimate issue that is the responsibility of the tribunal of fact. Though there are many exceptions in practice to the general rule as to not asking questions that by their terms call for an answer to the ultimate issue, it is a rule that is soundly based in its endeavour to reserve to the tribunal of fact the actual responsibility for the resolution of the ultimate issue. A third consideration is that there is inevitably much difference in the views of expert witnesses as to what constitutes a probability as opposed to a possibility, whether in terms of a particular case or simply as a matter of logic. There is the obvious danger that an expert when asked to provide an opinion as to whether a causal link exists may do so in terms of scientific proof that may be altogether too exacting for the degree of satisfaction necessary in a legal proceeding".

These observations apply equally to administrative proceedings where similar issues arise for determination.

1. The Tribunal has found that immediately prior to taking her holiday on 8 December, 1986 the respondent was carrying out the duties of a ward nurse at the camp hospital and that in the course of those activities she was required to attend on patients suffering from viral infections. That finding was open to the Tribunal on the evidence of the respondent and Dr. De Sousa. There was also evidence from the doctors, including Professor Burns, that it was possible that she could have caught the virus from one of the patients. The Tribunal has concluded, applying "common sense principles" that the degree of exposure at that time was appreciably higher than when she was at large in the general community in an open environment when on holidays. In those circumstances, the Tribunal concluded, as a matter of logic and on the balance of probabilities, that the increased degree of exposure to a concentration of people suffering viral illness led to the respondent's contraction of a virus at Puckapunyal and inferentially a contraction from one of the patients.

2. The applicant contends that the approach of the Tribunal contains two errors of law. The first is that taking the evidence at its most favourable to the respondent, the evidence indicated competing inferences of equal plausibility and in consequence the onus of proof as a matter of law, was not discharged (Nesterczuk v. Mortimore (1965) 115 CLR 140. The second is that on the evidence which deals with the level of risk to which the respondent was exposed (that of Professor Burns) the respondent was not exposed to a level of risk higher than that of the normal public.

3. The evidence of Professor Burns relied upon by the applicant was :-
   

"Well, if you were told that this woman was tending, in her occupation, patients who were suffering from a viral infection, would that be persuasive to you?---It - I mean she might have contracted it from them. I mean I guess you can put the same argument up to myself. I work in an environment where people have these illnesses all day every day and then I have my own children and then I go to public meetings. It is very very difficult to know. All right, there may be some specific viruses like the hepatitis virus that if someone who works in the health area might get, we know that, but from a public health point of view I don't think you can see apart from those specific viruses, that any of us is at more risk than anyone else".

1. The weight given to any evidence by the Tribunal is a matter for the Tribunal and it involves no error of law that the Court, if it had to address the factual issue itself, may have given a different weighting to the evidence. This case is quite different to the situation in Nesterczuk. There, there was a collision between two motor vehicles in the centre of the road and nothing more. Here, it is not simply a case of the respondent contracting a virus which, depending upon its period of incubation, could have been contracted from exposure to the virus either during the period of employment or when on holidays. There is the additional fact established on the evidence that in the course of her employment the respondent was working closely with persons suffering viral illness, and, within a time scale consistent with contracting a virus from exposure to the patients, she exhibited symptoms of a viral illness on 17 December, 1986, and again, within a time scale consistent with that viral illness acting as the trigger, demonstrated on 25 December, 1986 the onset of the disease encephalomyelitis. It was in my view open to the Tribunal to use the additional factual material to draw such inferences as were reasonably open to it from that evidence.

2. The Tribunal was not bound to accept the expert evidence of Professor Burns in relation to matters of common experience. Professor Burns acknowledged that it was possible that the respondent contracted the virus from exposure to the patients. Obviously, the Tribunal did not accept that the risk of catching a virus when caring for persons suffering from viral illnesses in a close environment was no higher than the risk to members of the public of catching a virus, if by that Professor Burns meant members of the public at large in the outside world, and not members of the public in hospital situations. Even if Professor Burns meant members of the public visiting a hospital, the Tribunal was not bound to accept this opinion. Nor should it be overlooked that the evidence of Dr. Waddy, even with the holiday period being put to her as being 8 - 21 December and not 14 - 22 December as she originally thought, generally supported the conclusion reached by the Tribunal. The risk of contracting viral illness while caring for family members in the family home, or cross-infection between members in the same household, is a matter of common experience within the general knowledge and experience of the Tribunal. Once Professor Burns acknowledged the possibility of contraction of the virus from the patients, the question of the probably of the link from that source to the viral illness of the respondent which triggered the disease was a matter for the Tribunal. In EMI (Australia) Ltd. v. Bes (1970) 2 NSWR 238, Herron CJ, with whom Holmes J agreed, stated the relevant principles thus (at 242) :-
   

"...that it is not incumbent upon the applicant, upon whom the onus rests, to produce evidence from medical witnesses which proves to demonstration that the applicant's contention is correct. Medical science may say in individual cases that there is no possible connexion between the events and the death, in which case, of course, if the facts stand outside an area in which common experience can be the touchstone, then the judge cannot act as if there were a connexion. But if medical science is prepared to say that it is a possible view, then, in my opinion, the judge after examining the lay evidence may decide that it is probable. It is only when medical science denies that there is any such connexion that the judge is not entitled in such a case to act on his own intuitive reasoning. It may be, and probably is, the case that medical science will find a possibility not good enough on which to base a scientific deduction, but courts are always concerned to reach a decision on probability and it is no answer, it seems to me that no medical witness states with certainty the very issue which the judge himself has to try". (See also Asprey JA at 243 to like effect).

1. There was in my view sufficient evidence to enable the Tribunal to draw the inference that as a matter of probability the respondent caught a virus while treating a patient at the Camp Hospital at Puckapunyal prior to her commencing leave on 8 December, 1986. Additionally, there was sufficient evidence for the Tribunal to draw the inference that this virus was the trigger which caused the respondent to suffer from encephalomyelitis. The approach taken by the Tribunal to the evidence and the conclusions drawn from it demonstrate no error of law.

2. It was further submitted by the applicant that the Tribunal misdirected itself in paragraph 24 of its reasons from its consideration of the decision in Treloar v. Australian Telecommunications Commission (1990) 26 FCR 316. I do not agree. The Tribunal in the passages cited in its reasons from Treloar's Case identify the two relevant issues, namely :-
   

(a) Did the employee contract a disease;

(b) Did some relevant aspect of the employment add their measure to the creation of the condition (the disease).

1. Here the Tribunal found that the disease was encephalomyelitis. The Tribunal found that the respondent, because of her exposure to patients suffering from viral illnesses in the discharge of her employment with the Army contracted a viral illness. It found that the exposure of the respondent to the risk of contracting a viral illness was of a greater degree than she would otherwise be exposed to in ordinary life. This was because of the nature of the work and the manner and place of its discharge which regularly exposed her to more people suffering from viral illness in the one place than would occur in the outside world. This constituted a state of affairs sufficient to establish the employment as a contributing factor if the state of affairs was shown to have played some part in the contraction of the disease (Federal Broom Co. Pty. Ltd. v. Semlitch (1964) 110 CLR 626 at 632; Treloar at 332). The Tribunal found as it was entitled to do, having regard to its other findings and the medical evidence, that the virus, which the respondent contracted in the discharge of her duties as a nurse, triggered the encephalomyelitis and thus the employment was a contributing factor within the meaning of section 29(1) of the Act to the respondent's contraction of that disease.

2. The applicant has failed to demonstrate any error of law in the decision of the Tribunal.

THE COURT ORDERS:
30. That the application is dismissed.