No one is alleging fraud or illegal conduct in the Air Australia collapse and on the face of it there hasn't been.
Reportedly $36M in forward ticket sales collected. Reportedly sales made and money collected up to the night of shutdown. Debts of $90M. Only $400K in the piggybank.
I'm no lawyer, but you would have to be suspicious that there has been some conduct there that is illegal in relation to the corporations act - intentional or not. I believe ignorance of the law is not a viable defence. Whether it is pursued is of course another matter.