The law doesn't permit a life-saving doctor to be a serial killer on their days off "as long there's net life saving". But it does permit drugs that save many lives but might kill some people too. Agency matters to the law (and that's usually the proper approach imo).

The problem is the chat logs look a lot like ChatGPT is engaging in behavior a lot like a serial killer - it behaved like a person systematically seeking the goal of this kid killing himself (the logs are disturbing, fair warning).

Even more, the drugs that might save you or might kill you (theoretically) aren't sold over the counter but only prescribed by a doctor, who (again theoretically) is there to both make sure someone knows their choices and monitor the process.