There can be more than one 'spouse'. In general, a legally married spouse remains a spouse (even if separated) unless or until formally divorced. The spousal status of a de facto partner however, endures only while living in a joint household with the employee.
Thus, it is possible for an employee to have two spouses, i.e. a person to whom he/she is still legally wed but separated from without divorce, and the person with whom he/she is currently living with, i.e. on a de facto married basis. Furthermore, the employee may be contributing to the absent spouse's upkeep which would keep that person within the definition of 'dependant'.
In such a situation, the resident spouse (i.e. the de facto), will be entitled to receive compensation on the basis of Ss4(5) and only in unusual circumstances would she have to share that compensation with the legally married spouse. This could occur where the legally married (but absent) spouse can demonstrate total dependence on the employee for economic support. This is an unlikely, but possible scenario.