I'm not doubting anything your saying, but calling someone who is being murdered by the state the patient is icky, even if the methods being used are analogous to those used on patients who are receiving medical care. It also underlines the point that, of course the victim resisted because they were being killed, compared to a dental patient who is willingly undergoing a procedure they can expect to wake up from. Nitrogen hypoxia may be an effective way of administering a humane death to a willing participant, but in some ways giving a false perception of control to the victim (as long as I can hold my breath I won't die, as obviously futile as that may be) is undermining all of the considerations of physical discomfort that go into describing the process as humane