Fathom perhaps you are not up to speed with the way CASA write their questions in these exams?
It becomes more a point of being able to derive what they are actually asking to the degree of needing to be a lawyer, and the ridiculously subtle differences in the answers they provide, more than actually having knowledge of the subject or where to reference things in the documents.
Not saying it's an excuse for not being able to interpret the docs but I can sympathize with anyone who gets 4 of CASA's questions incorrect out of 30.