Just a note for those who want some legality background info. The way the law works in Canada, you need consent to administer medical treatment.

With adults it's easy, you ask them. However with unconcious adults, consent is implied, and judges usually rule "had they been given the option while awake, it's assumed they'd want to live".

With children, consent lies with the parents, unless the condition is life-threatening, and then consent is implied, and the law allows medical personnel to go ahead without a court order, even against the parent's wishes. It's the first thing you learn in a First Aid course in Canada.

The only thing they needed the court order for was to be able to remove the children from the parent's custody in order to administer the treatment. The courts didn't touch on whether the treatment was "right" or not.

So JulieM, I doubt the parents have an argument with regards to common law, because established precedent is that when a child is in a life-threatening situation, the parents' wishes have no standing.