The difference is in how abuse of the given system affects others. This AI affected this person and his actions affected himself. Nothing about the AI enhanced his ability to hurt others. Guns enhance the ability of mentally unstable people to hurt others with ruthless efficiency. That's the real gun debate -- whether they should be so easy to get given how they exponentially increase the potential damage a deranged person can do.
That's why I don't buy the "an LLM is just a tool, like a gun or a knife" argument. Tools don't talk back, An LLM as gone beyond being "just a tool"