Is a Trading Halt coming ?, page-67

With due respect I haven't read anywhere in the company documents that the offer is in fact underwritten by the broker.
Otherwise they wouldn't need to include a "Shortfall Document".

Shortfall Offer
Any New Shares under the Entitlement Offer that are not applied for will form the Shortfall Shares. The offer to issue Shortfall Shares is a separate offer under this Offer Document (Shortfall Offer). Under this Offer Document, the Company offers to issue the Shortfall Shares to investors at the same price of $0.02 per New Share as that offered under the Entitlement Offer. The Shortfall Shares will have the same rights as the New Shares as detailed in Section 2.13. Other investors may apply for Shortfall Shares by completing the Shortfall Application Form upon invitation from the Company (refer to Section 3.3). Shortfall Shares may be allocated to investors who apply for Shortfall Shares under the Shortfall Offer, at the absolute discretion of the Directors. Eligible Shareholders may not apply for Shortfall Shares. Shortfall Shares will not be offered or issued to any Applicant if, in the view of the Directors, to do so would increase that Applicant's voting power in the Company above 19.9% or otherwise result in a breach of the Listing Rules, the Corporations Act or any other applicable law. An Application for Shortfall Shares accompanied by payment of Application Monies does not guarantee the allotment of any Shortfall Shares. The Shortfall Shares will be allocated within three months after the Closing Date.

So these shortfall shares can actually go to ANY investors who wish to buy.