You can't argue with libertarians like that. If you distill his argument, he's basically saying that he would rather let people die than have their basic needs

You can't argue with libertarians like that. If you distill his argument, he's basically saying that he would rather let people die than have their basic needs met by income redistribution. "I got mine, so fuck you", is basically it. That view is completely antithetical to the core belief system of progressive liberals and it's not something you can really have a discussion about. It's like arguing over whether God exists.