Call it what you will, I think there are a lot of medical ethicists who would disagree and call DNR orders passive euthanasia. It only makes logical sense when you think about it.
I think we have to have a new way of looking at these things. It's not "suicide", "murder" or anything in the traditional sense of those words. It's an end of life decision, which should be reserved for only the most drastic cases. Heart disease, which a patient can recover from and which can be controlled, regardless of whether it will recur or not, would not qualify. Late stage cancers, which are literally destroying and consuming someone, would be. We are lucky enough to be living in an age where health care is so great that we can extend our lives if not outright cure diseases that we could not before. We can prolong our lives to a great degree, and the longer we live, the more likely we will experence a dreaded disease. Which is not to say that terminal disease only ocurs in our older people, it does not. Why would we want to involve others in such a thing? Because it's familial and societal - our loss will be felt on those scales, and while it is happening to the ill person primarily, it also affects their loved ones, and society at large. Just because something isn't legal, doesn't make it immoral. Laws reflect a society's views at the time, and throughout history, they have not always been moral.
I agree also that there is not such thing as "individuals" involved in making these kinds of decisions - there's only ever one individual involved, IMO and that is the ill person. Everyone else involved is seeing to it that the patient's wishes are respected while giving them the best care possible, and that they have come to the decision freely. This particular case bothers me because we don't know if the man was honoring his partner's wishes or not, and the method is rather violent, IMO. It should be left in the hands of health care professionals, where it belongs.