But what you are responsible for changes: in that case if you were to accidentally kill someone you would be at most responsible for negligent manslaughter, not murder, and to what degree that could stick would depend a lot on the details of the case. It's also up to the law to define what level of negligence amounts to criminal liability, so you can't just work by analogy: it matters whether there is a law on the books that criminalizes unauthorized access to a computer system by negligence on your part, which I suspect there is not at the moment.
In my mental model, the best analogy to AI agents and their blast radius is a gun.
If you are playing with a gun, it goes off and hurts someone - you are responsible despite intent.
But what you are responsible for changes: in that case if you were to accidentally kill someone you would be at most responsible for negligent manslaughter, not murder, and to what degree that could stick would depend a lot on the details of the case. It's also up to the law to define what level of negligence amounts to criminal liability, so you can't just work by analogy: it matters whether there is a law on the books that criminalizes unauthorized access to a computer system by negligence on your part, which I suspect there is not at the moment.