“The court has given a clear ruling but on one point they have a very different view,” he said by phone, referring to the prosecutors’ belief that the doctor should have made greater efforts to confirm that the patient still wished to proceed with euthanasia.

“Even though she was suffering from dementia, you should check that as the physician, with the patient, and you should be 100 percent sure,” Mr. Zonneveld said.

The case was the first of its kind to prompt a criminal investigation since 2002, when the Netherlands became the first country to legalize euthanasia.

Questions are often raised about the parameters for those wishing to end their lives and about who should be allowed to take that step, and lessons from the Dutch system often reverberate internationally. The debate can be particularly complex when dementia patients are involved, and opinion is often divided almost on a case-by-case basis.

In 2017, after reports of an increase in euthanasia among dementia patients in the Netherlands, and of a growth in the practice of administering sedatives before lethal injections, a group of more than 200 doctors signed a letter urging against euthanasia based on advance directives from patients. The doctors argued that they were reluctant to end the life of people who could not confirm that they still wanted to die.

Dr. Scott Y.H. Kim, a psychiatrist and bioethicist at the National Institutes of Health in the United States, wrote in an email that, “When a human being is resisting — regardless of how ‘meaningless’ the action is in terms of intentions and understanding — and what she is resisting is an act to end her life,” then it could be “pretty difficult to take in.”

The Dutch law on euthanasia contains strict rules, known as due care criteria, that must be met in every case.