No not correct as the contract was signed by Justin Madden in 09 under the Labor government. Lib therefore would have had to break the contractual agreement in order to change.Bracks signed the papers to approve funding. If the Libs had the powers to turn the unions into paper tigers like you claim, nothing would have stopped them from exercising said powers in any of the three years it took to build the plant.
But I like where this conversation is going, do tell how unions sometimes make workplaces more dangerous than they ought to be.