Mr P
I would explore the oppurtunity, Find out who called you and where your file is, Doubltful that you would be able to do FSP again but proabably get a chance at another board. RAAF pilot is still very competitive but if you want to consider Army or NAvy then your chances increase substantially.
I got in at the grand old age of 27 so don't close any doors, most of the guys on my course are 22-23. If you want something badly enough you will get it but don't go into it thinking that its an easy way to an airline job you should want to be a military pilot above everything else.