Jindalee Operational Radar Network
If this latest find west of Australia turns out to be the missing aircraft I'm wondering if Australia's over the horizon radar (Radar Jindalee Operational Radar Network) wouldn't have already detected its final flight?
I think its possible that there are military surveillance systems which are capable of detecting large aircraft in this part of the world from a long distance away, and that its possible that government agencies wouldn't want to disclose their technological capabilities publicly for security reasons.