>If I train that other group, if I teach them how to hack computers and give them incentives to do so, and then I leave my computer open so they can use it for whatever purposes they chose, then I would expect to be held at fault.

Even that analogy doesn't really work:

For "dumb" things: you can "train" (ie. write) hacking tools but as long as you put a disclaimer that it's for "educational purposes only", you're in the clear, even if some baddies decide to use it.

For "smart" things: you can "train" people to hack for you, but as long as you say it's for legal purposes (eg. vulnerability research or red-teaming), you're also in the clear, even if some of your trainees go rogue.