JB has summed it up nicely. One of the possible scenarios for the next few years is that J* returns the A330's to QF but keeps the J* crews flying them and wet-leases them back to QF. It sounds like a winner in theory to any beancounter until this sort of situation occurs.
QF could concievably have 10 A330's flown by QF pilots and eight flown by J* pilots. All of them non-interchangeable under the current system. Did anyone think of this in the rush to introduce the "B"Scale into Qantas?
If this situation is attempted to be circumvented by a regulation change, think of the legal ramifications as a Judge, (and it would go to court) tried to unravel the logic. "Lets see, you want two different groups of pilots flying the same equipment, on the same routes, in the same uniforms, using the same procedures under the same AOC, with half of the pilots being paid 40% less and under different scheduling rules and Terms and conditions?!?"
Of course I could be wrong and this may be fixed by a simple reg change. But if it cannot, then the grand design would be thrown into a state of flux, with possibly both pilot groups, QF and J* being the winners.