I don't think it's okay to kill another living person.
Because you didn't just kill off some random human. You could have killed a parent, a sibling, a best friend, a love. It's wrongful to just take that all away from someone who was completely healthy. It's a different story if this person was in a coma, and their family had decided to pull the plug. With that, you know that they probably won't come back, or will come back with horrible repercussions. But a healthy person has their whole life ahead of them.