13 For the purposes of the present case it is important to note that in the third step, the AAT is limited to asking whether the facts raised by the claimant give rise to a reasonable hypothesis. Proof of facts is not in issue at this point. See also Harris v Repatriation Commission (2000) 31 AAR 270 ("Harris") at 279-281 per Finn J.
14 The SoP that was in force at the date of the Commission's decision was Instrument No. 105 of 1995 (entitled Statement of Principles concerning Lumbar Spondylosis) which was amended by Instruments No 334 and 358 of 1995 ("the 1995 SoP"). The SoP that was in force at the date of the decision of the AAT was Instrument No 27 of 1999 (entitled Revocation and Determination of Statement of Principles Concerning Lumbar Spondylosis) ("the 1999 SoP").
15 At the AAT hearing the appellant and the respondent agreed that the applicable SoP was the 1999 SoP which, accordingly, was applied by the AAT. Subsequently, a Full Court in Repatriation Commission v Keeley (2000) 98 FCR 108 held that, subject to a contrary intention, it is to be presumed that the SoP to be applied is that in force at the time of the Commission's determination which, in the present case, was the 1995 SoP. The Full Court concluded that, as rights accrue under an SoP, where the SoP applicable at the date of the Commission's decision is more beneficial than the SoP that replaces it, the earlier SoP is to apply unless a contrary intention is clearly disclosed. Lee and Cooper JJ at [46] said that in respect of beneficial legislation, such as the VE Act, it may be concluded that Parliament
"intended that the review of a decision on a claim made pursuant to a Statement more beneficial to a claimant than the terms of a Statement that replaced the former Statement after the decision had been made, is to be conducted as if the former Statement had not been revoked."
16 See also at [80-81] per Kiefel J.
17 It seems to be implicit, if not explicit, in the approach of the Full Court in Keeley that a contrary intention might be found if the terms of a later SoP are more beneficial to a claimant than the terms of the SoP which it replaced. Of course, the contrary intention must be discerned from all of the terms of the later SoP and not just particular aspects of it.
18 Applying the reasoning in Keeley to the present case, subject to contrary intention, the applicable SoP was the 1995 SoP, being that in force at the time of the Commission's decision. The appellant contended before the primary judge that the 1999 SoP applied by the Tribunal was more onerous than the 1995 SoP and that the 1995 SoP ought to have been applied, notwithstanding the appellant's agreement at the AAT that the 1999 SoP was applicable. Before this Court the appellant contended that the 1999 SoP was more beneficial and therefore was properly applied by the AAT.
19 Both the 1995 and the 1999 SoP listed the factors that must, as a minimum, exist before it can be said that a reasonable hypothesis has been raised connecting lumbar spondylosis with the circumstances of the operational service rendered by a veteran. For present purposes the relevant factor in the 1999 SoP was factor 5(h) being, "suffering a trauma to the lumbar spine before the clinical onset of lumbar spondylosis". The 1999 SoP relevantly defined "trauma to the lumbar spine" as meaning:
"…a discrete injury to the lumbar spine that causes the development, within 24 hours of the injury being sustained, of acute symptoms and signs of pain and tenderness, and either altered mobility or range of movement of the lumbar spine. These acute symptoms and signs must last for a period of at least seven days following their onset."
20 The same factor was listed in the 1995 SoP. The counterpart definition of "trauma to the lumbar spine" in the 1995 SoP was relevantly defined as meaning:
"…an injury to the lumbar spine caused by the force of an extraneous physical or mechanical agent that causes the development, within 24 hours of the injury being sustained, of acute symptoms and signs of pain, tenderness, and altered mobility or range of movement of the joint, and where such acute symptoms and signs last for a period of at least one week immediately after the injury occurs, unless medical intervention has occurred."
21 The primary judge identified the differences between the definitions in the 1999 SoP and the 1995 SoP as follows: