Now that you've mentioned it Xcel, that phrase about a PPL holder only logging command does if they are the sole manipulator of the controls sounds awfully familiar.
If that is the case then perhaps the PPL can only fly as co-pilot not PIC.
The other thing is people arguing about (for simplicity a CPL in a CHTR op) people logging co-pilot time in a SP aircraft. C208/PA31 or B350 even. Often these arguments are involving overseas regs which are quite different but I'm fairly sure there is nothing to stop you logging it if you are acting in any piloting capacity in AUS.
Can anyone find anything specifically about it?