There are two things here I don't get:
a) why on Earth would you want to switch your GPS
off on final approach? Beats me....
b) the report states 'C of G
probably out of limits'. Why 'probably'? With two survivors it must be possible to determine who sat where, the weights of then pax should be known with reasonable accuracy and and fuel quantity also. Unless, of course, they did the calculations (as I'm sure the ATSB would) and found that it was either just outside or just within limits.
Anyway, sad event.