According to the AP postage pages, standard post parcels now come with up to $100 compensation so I would lodge an enquire via Messenger to Aust Post.  They may even be able to confirm that a) the parcel redirection was requested by the receiver and/or may be able to confirm delivery even if the tracking shows “in transit”.  Had that happen to a return, tracking showed “in transit” but AP were able to confirm the parcel was in fact delivered.  It’s worth a try and you have nothing to lose!

let us know how you go!