This is apparently the official word

"the accused, Nguyen, was on transit from Cambodia to Australia. He never actually stepped out of the airport but was in the transit lounge and was stopped there. So in terms of the Australian Government's argument is that he should be judge in accordance to Oz laws as he was "not" in Singapore but in transit and was in fact under international law, in this case the Oz government's argument is that since he's on his way to Melbourne, he should be tried under oz laws."