Ann: Update on Takeovers Panel Proceeding, page-4

It will 100% NOT cost them $18m.

"THE PANEL ORDERS
1. The Sale Shares are vested in the Commonwealth on trust for ARN.
2. ASIC must:
(a) sell the Sale Shares in accordance with these orders and
(b) account to ARN for the proceeds of sale, net of the costs, fees and expenses
of the sale and any costs, fees and expenses incurred by ASIC and the
Commonwealth (if any)."

They get the proceeds of the sale so loss is difference between price paid and amount they sell it for.

Plus they have a near air tight case against their advisers for negligence in not determining the status of Allan Grays' shareholding prior to the acquisition = loss will almost certainly be covered by M&A insurance.