Claims for injuries are fairly straightforward as there is a discrete event that occurs at a period in time that dictates which Act applies. If the injury is prior to 1 July 2004 then it is VEA and or SRCA; if it is on or after 1 July 2004 then it is the MRCA.
Claims for diseases which develop over time, such as osteoarthrosis and psychiatric conditions, are not as straightforward. For these types of conditions, the determining consideration in regard to which Act applies is which period of service contributed to the development of the disease. It is important to remember that the MRCA allows for liability to be accepted where the contribution is before, and on or after 1 July 2004. For MRCA to potentially apply for this type of condition, the disease must either have onset or have been aggravated after 1 July 2004.
As a starting point, any disease that meets the above conditions should be considered under the MRCA first, regardless of the contention. The disabling provisions in the VEA and SRCA indicate that those Acts do not apply where there is a contribution from MRCA service.
If the disease cannot be accepted under the MRCA, only then would you consider whether it could be accepted under the VEA and/or SRCA.