QFF Affiliated Credit Cards in the U.S

[NM]

I've never tried this - cause i know it is wrong, but I'm just wondering, what happens when someone double dips and claims points at both ends. e.g. claims points with Qantas and AA for the same flight?

Does one airline have precedence over the other? Do you get penalized and they take away all your points?

Just wondering....

Very unlikely to happen. Your boarding pass will generally have a reference to the FF program to which the points/miles will be paid. If you send a copy of that BP to the other airline they will not allow credit. And if you use a BP without any reference to FF program and try to claim, then the FF program will always contact the operating airline for confirmation that you did actually travel and that they are going to pay the points/miles. And if they have already paid one FF program for the points/miles then they will not pay out again for the same passenger on the same flight.