R.L. says "But who would want to live like that?"

Tom says: "Really? The idea of "wanting" something or other implies that someone is still in there, doesn't it? If she's just a piece of breathing meat, what difference does it make to her or anyone else if I keep her breathing? ..."

Good point. I don't think I thought of that.
At most it's only symbolic or may some kind of sense of "honor" which could be the only concern, real pain even discomfort for the patient can't be the issue.
It's kinda in a way the reverse of pain test in "Dune".
If she is actually experiencing pain then she got more awareness than anyone who is drugged for a medical operation- therefore should not be considered brain dead. Pain, the sense of time, and other perceptions are not objective rather they are subjective "things" requiring the signal to be processed in order "realize" it's existance. For instance it's possible to lose a sense time even when conscience, and in conditions shock (in which a person can be conscience- can talk and chew gum) a person can unaware of pain.