Odds: If it was last Friday, very low now. If it was the Friday's before, next to nothing.

The couple of times I have lost property QF have always been able to reunite me but that was once my carry on suitcase left in the lounge and I realised upon disembarkation at the other end by which time it was still sitting where I left it. The other time the aircraft was still at the gate disembarking and it was only a jacket.

Where as you are relying on the goodwill of the person who sat there after you being honest and handing an item back to staff. If it was handed to staff you will get it but I expect you would already have been matched up by now.

Chances are the low life has taken it themselves but I hope I am wrong.

I hope your device was secured.