It's a FAR away game, he's had to turn his clock backwards 20 years to enter QLD.
NT is a territory and not a state, therefore pretty much makes it's own rules where the sit on just about everything. If it didn't effect the rest of the country they'd probably choose to have 28 hour days just to have more drinking time.
SA's time zone was selected because the vast majority of the state live in the right hand third of the timezone. It means they are closer in time to the eastern states where true or not in this day and age business and the majority of the country's decisions are made.
To make matters even more confusing there is an unofficial time zone of 1 hour 30 minutes on the opposite side of the SA time zone. That time zone runs partially up the WA boarder and into NT but not all the way to the top, it also runs about 300ks into WA at the bottom of the country but not the top. Then we have towns like Broken Hill which are within NSW borders but use central time.
I'm sure we do it just to confuse tourists. But I used to love driving east in summer, I could do a 14 hour day and only claim 11 (the max in 24 hours) on the log book, it was technically wrong and could be easily checked but it never was.