Anyone could say that the injured "didn't want to live like this." Isn't that like saying "Joe really wanted all his money to go to me" in the absense of a will?
Sadly, most physicians don't take the oath anymore...
Oath of Hippocrates "Above All, Do No Harm"
I swear by Apollo the physician, and Aesculapius, and Hygeia, and Panacea and all the gods and goddesses, making them my witnesses, that I will fulfill, according to my ability and judgment, this Oath and covenant: To hold him, who has taught me this art, as equal to my parents, and to live my life in partnership with him, and if he is in need of money to give him a share of mine, and to regard his offspring as equal to my brothers in male lineage, and to teach them this art if they desire to learn it without fee and covenant; to give a share of precepts and oral instruction and all the other learning to my sons and to the sons of him who has instructed me, and to pupils who have signed the covenant and who have taken an oath according to the medical law, but to no one else. I will apply dietetic measures for the benefit of the sick according to my ability and judgment; I will keep them from harm and injustice. I will neither give a deadly drug to anybody if asked for it, nor will I make a suggestion to this effect. Similarly I will not give to a woman an abortive remedy. In purity and holiness, I will guard my life and my art. I will not use the knife, not even on sufferers from stone, but will withdraw in favor of such men as are [skilled] in this work. Whatever houses I may visit, I will come for the benefit of the sick, remaining free of all intentional injustice, of all mischief, and in particular of sexual relations with both male and female persons, be they free or slaves. What I may see or hear in the course of treatment or even outside of the treatment in regard to the life of men, which on no account [ought to be] spread abroad, I will keep to myself, holding such things shameful to be spoken about. If I fulfill this Oath and do not violate it, may it be granted to me to enjoy life and art, being honored with fame among all men for all time to come; if I transgress it and swear falsely, may the opposite of all this be my lot.