We had one case about 6 years ago here in Atlantic Canada. A young female doc and a 42 year old male throat cancer patient. She was suspended from practicing medicine for life and demoted to working in the lab. It was the patient's family that went after her. I can only assume it was for money.
In the "decision", the "head medical guy" said, in his report and on TV, that "she chose the wrong drug." Essentially, reading between VERY fine lines, he said what we all were thinking and hoping. That being, that such relief can be had, but it has to be "properly done". Now, that is little solace for those facing such extreme circumstances, but still, a glimmer of hope.
(In case you are wondering... she killed him with a drug that "kills", rather than killing him with an overdose of a similar drug that would be used during a regular medical procedure. So, she made a serious error in judgement when she allowed a paper trail that could prove that she did what he begged her to do. After all, it IS illegal to treat humans better than pets. So sad.)