I don't think it has any direct bearing on your situation, but I have a data point: my wife recovered her iPhone left in the seatback pocket. ASP-ADL flight, and realised about 35 mins after disembarking. I immediately called the QP in ADL, thinking that I might be able to get a human who could call the gate agent, which I did and she did, but by that time the plane had pushed back and was headed to MEL. The QP lady called me back later and said that she had contacted the flight manager and that the flight manager promised to leave the phone at MEL lost and found. Sure enough, three days later we drove into MEL (which was part of our journey anyway, fortunately) and my wife ducked into the terminal and came out with the phone after me making only one lap of the airport. Needless to say, I left very effusive compliments about the service and in particular the extremely helpful woman at the ADL QP.

Good luck!