There is nothing that could prevent a bad actor from replicating exactly the same thing with the given goal of e.g. gaining control of critical infrastructure or extorting money. Except for maybe economics.

Same can be said about a hundred other things in the world. All the way from knives to nuclear.

Letting bad actors dictate the pace of technological development is certainly one option, but not a good one.

Bad actors could and will train their own models eventually. So what's the point of crippling frontier? It will only delay preparations for dynamic of new world prolonging the fake sense of relative safety and temporarily lowering motivation to find actual robust mitigations.

There's nothing stopping anyone from doing it, even without AI. People have proved entirely capable of doing a lot more hacking than happened here.