3.5.4 Balance of probabilities (BOP) cases

The standard of proof that applies to liability claims relating to peacetime service is the 'balance of probabilities' or 'reasonable satisfaction' test.  To accept the claim, a decision maker must be reasonably satisfied, on the basis of the available medical and factual evidence, that it is more likely than not that claimed condition X (injury, disease or death) was caused by contention Y (which in turn needs to be related to service).

The MRCA is regarded as 'beneficial legislation'.  This is a narrow legal concept which applies where particular legislative provisions are uncertain or ambiguous.  In that case, decision-makers are entitled to adopt an interpretation of the provisions that is more generous or ‘beneficial’ to a client.  Most of the provisions relating to the determination of liability are well-established, supported by relevant policy and case law and not ambiguous.  It is therefore not usually open to delegates to interpret the liability provisions in a different or more generous way, or on a case-by-case basis.

The concept of ‘beneficial legislation’ does not mean that a client can be given the ‘benefit of the doubt’ in relation to a claim, where the evidence is not sufficient to support liability on ‘the balance of probabilities’.  Where the evidence does not satisfy the delegate on the balance of probabilities that the claimed injury meets the relevant legislative requirements for liability to be established, it is not open to the delegate to determine that liability is present.  The concept of ‘beneficial interpretation’ is not concerned with remedying substantive deficiencies in the evidence or the applicant's case. Applications which fail to meet the ‘more likely than not’ standard should be decided in the negative.

However, in reaching a decision, a delegate is often required to weigh up different or competing information and decide which evidence is to be preferred.  In so doing, it may be open to the delegate to prefer the evidence that supports the claim, as long as that evidence is sufficient to satisfy the delegate that it is more likely than not that the claimed condition was caused or aggravated by service, having considered and weighed all the evidence available.