Good post Fugasi, definitely a possible outcome. However, I see...

Good post Fugasi, definitely a possible outcome. However, I see a couple of issues which would lead to a denial as just a likely outcome. Politicians will generally avoid controversy and try to please as many parties as possible. Your above scenario will anger the Greens, cause a media storm with the activists and allow the opposition to jump on the PM for another broken promise. Yes they said they will follow due process, but that was said at the same time as they were saying they are dead set opposed to the project, which can be seen as them waiting until they have an ironclad case for denial.

The spin they can put on it would be something along the lines of:
We are pro gas, but not at the expense of our pristine coastal waters (Greens, activists, possibly large % of population happy, avoids media storm)
We have recently announced a 10 gas supply deal (Industry happy, general population happy)
We continue to approve new projects, including projects for Woodside and Santos (Industry big players happy, reputation within industry kept intact)
We always maintained that we were against this project, and unlike the opposition we have finally buried it and follwed due process in doing so (Political reputation kept intact, no broken promises, no ammunition for the opposition)

The above will need an air tight legal case for denial, which I think is what they are working on. Like many have said, there have been several perfect storm moments recently for approval, and it has not come. Someone alluded to yesterday that it is unlikely that State Labor and Fed Labor arent working together on this. I would say the new bill will play a role in the denial of the project, but far smarter people than me will be putting that case together. Also, DB will still challenge the case regardless of the reasons given.

The above is just spitballing a possible outcome for how they may spin a denial, and why the decision is taking so long. Obviously its just a theory. Like I said, good post, and could see your scenario playing out also.