My home town, our main hospital.

The way things work here with kids is that the judge makes the decision based on what is best for the child. Children's well being, in this case health, comes before anything else, including parents desires. So in this case what is the best, most reliable outcome for the child...a transfusion. Not some unproven new idea, not prayer.
This sort of outcome came about after years of shitty and messy divorce cases where the kids came off second best compared to at least one of the parents. Everyone got annoyed. The legal system basic said "screw this, ethically the best solution is that kids come first and adults can deal with it". That's the price of being an adult, if you have an issue then go open a can of toughen-the-fuck-up, society protects those with the least power.
If the alternative treatments were easily available in Adelaide it would be a non-issue, however they are not and the judge is required by law to provide an outcome that maximises the benefit to the child.