I find it difficult to believe that VICPOL has the time, and the interest to bung on a Cecil De Mille production in regard to the phone, etc.. it just does not jell with the usual pragmatic approach VICPOL usually takes, ....
My take on it, the owner of the property saw the phone when the level of the dam went down, as dams do suddenly in very hot weather, the level drops overnight, and contacted the police. Of more interest, to me, are the other 'artifacts' they found at the same place, which, to my mind negates the idea of things being hurled from outside the property over the large bushy fence... hard to get a whole lot of things to land in the one spot. So , I think the phone and the artifacts , whatever they are, were dropped from the inside of the property. not the outside. FWIW.