I think it is as much a dilemma for a Buddhist as anyone else. On the one hand we have a very solid belief that killing is a wrong thing to do. On the other, there is the problem of the frame of mind of someone entering the Bardo. Finding oneself in the Bardo, fresh from the experience of agonizing pain, or with a head full of weird experiences induced by morphine or something, is not going to help you navigate the Bardo well.
Ideally, death should occur in a peaceful place free from pain and intoxicants, with a clear mind well focussed on virtuous objects. Such fortunate circumstances are a matter of karma, which makes it pretty important to get to work on that right away.
Sergeant Schultz knew everything there was to know.