The "side deals" that exist for Jetstar Asia are by no means illegal or deceitful. Qantas just controls Jetstar Asia through a series of management and loan agreements, allowing them to circumvent (legally) the law in Singapore on foreign ownership of airlines. Qantas takes on the entire financial liability of the company and derives the full financial benefit (if any) - just as they do with Jet Connect. Jet Connect is a 100% owned subsidiary and also does not appear under investments accounted for under the equity method - same for Jetstar Asia.
The only conclusion I am trying to draw from the above is that Jetstar Asia effectively functions as a subsidiary of the Qantas Group, nothing more and nothing less - and what they are doing is legal. Virgin Australia has also pursued a similar structure that Qantas has done with Jetstar Asia (and it's Ansett International that pioneered that split structure in Australia anyway)
As to whether Jetstar Asia has made a good return on investment, has been positive for shareholders, or whether there is a leasing rort going on between interested parties and Qantas subsidiaries - that's out of the scope of the conclusion I was trying to draw from my analysis. However, chasing silly investments, trying to launch an LCC in HK despite the airport's congestion and domination by CX, or pulling out of Frankfurt despite 90% load factors - is by no means a crime.