“The right of mature adolescents not to be deprived of their medical decision-making autonomy means that the assessment must be undertaken with respect and rigour,” wrote Justice Rosalie Abella.

“The more serious the nature of the decision, and the more severe its potential impact on the life or health of the child, the greater the degree of scrutiny that will be required.”

“In some cases,” she added, as the Globe and Mail reported, “courts will inevitably be so convinced of a child’s maturity that the principles of welfare and autonomy will collapse altogether and the child’s wishes will become the controlling factor.”

At issue was a Manitoba law that allows authorities facing a life-or-death situation to forcibly remove children under 16 from their homes so they can undergo unwanted medical treatments. The plaintiff was A.C., a girl suffering from internal bleeding who received a blood transfusion against her will three years ago when she was 15. She and her parents, who are Jehovah’s Witnesses, argued the law violates freedom of religion.

But while the court upheld the law, David Day, A.C.’s lawyer, told the Globe and Mail she was nonetheless “elated” that it had recognized that “she had the right, as a mature, informed 15-year-old, to have her medical treatment decisions respected.”

In his lone dissenting opinion, Justice Ian Binnie argued that A.C. had the absolute right under the Charter to let her religion determine what is in her best interests.

“The Charter is not just about the freedom to make what most members of society would regard as the wise and correct choice,” he wrote. “If that were the case, the Charter would be superfluous.”

Queen’s University law professor Nick Bala suggested that Abella’s “sophisticated” ruling could also impact situations where parents and teens disagree. She is “clearly recognizing,” he said, “that minors under 16 have ability to make decisions without their parents’ involvement about abortion, contraception and other matters that are not life-and-death decisions.”