8. The role of the Commission and of the Tribunal should not be misunderstood. Their function was to decide a question of fact or of mixed fact and law. They were not, on the evidence, bound in law to find for the claimant. Even where experts differ, as here, it is open to the Tribunal to be satisfied beyond reasonable doubt that there were insufficient grounds. A conflict of testimony (expert or otherwise) does not require that the claim be upheld (anymore than in a criminal trial it would require an acquittal) although often it would have that result. Nevertheless, it is not enough that the Tribunal prefer the evidence (including opinion evidence) which tends to disprove the claim. Even if it rejects the evidence in favour of the claim, the claimant is entitled to succeed unless the Tribunal is satisfied beyond reasonable doubt that there are insufficient grounds for the claim. In the light of Sir Edward Dunlop's opinion I find the Tribunal decision astonishing, but in law, because there was evidence which if accepted disproved the claim, the Tribunal was entitled to be satisfied beyond reasonable doubt that there were insufficient grounds, and, were it not for its errors of law, it is difficult to see how the decision could be disturbed. For this reason it should be stressed that the duty of the Repatriation Commission and the Repatriation Review Tribunal is to implement the onus of proof section not to frustrate it. (at p640)