I expect their terms and conditions permit them to do almost anything they please. But if the points have already been spent/transfered then it will be a lot harder for them to do anything about it :wink: .
They may not be able to get it back from Qantas easily but they can put a negative amount against your accrued ANZ FF points. I had this done to me last month when money from a Qantas flight I cancelled came back. The points I got for spending the money in the first place had already been credited to my Qantas FF account but I had a negative 480 points to accrue before I got into positive territory again.