correct: If ASIC suspects that a transaction breaches the rules...

correct: If ASIC suspects that a transaction breaches the rules they can order the shares sold.
Also some points:
At the moment any T/O attempt would need to be hostile,
A hostile bidder can obtain 19.99% before launching a bid.
However, before that happens a 5% holding and any further purchase would need to be disclosed.
All hostile bids are protracted and expensive, most boards would not allow, and rarely achieve anything.
It's currently unclear who is in bed with whom?
It seems that the Interest may be from the US?
Small matter of FIRB approval, and, given the strategic value of the the metals...unlikely

In the meantime, await the JORC/s and a nice fat, juicy offer, that, In my opinion, is the only way that POS will be taken-out.

cheers XanaX