Since the consent to euthanasia was conditioned on "when she felt the time was ripe", once her cognitive abilities declined to the point that she could no longer participate in decision making that condition became impossible to meet. The consent should have effectively been revoked then and there.

The fact that they surreptitiously drugged her tells me that they knew they did not have her consent, further reinforced by her physical resistance when she became aware of what they were doing. I'm pretty sure this person would have been convicted in the US; the son in law too. And the civil trial- holy shit, the optics of shoving down a struggling 74-year-old woman so they can jab her with a needle with a lethal poison would make any plaintiff's attorney lick his chops.

Opponents of euthanasia have always said that it's a very short step from voluntary suicide to the state making the decision for you, for which they are roundly mocked as arguing a ridiculous slippery slope. But between this story and Canada actively trying to sell people on getting euthanized, it looks like they were right all along.