We've been using "agent decides to do X" for at least 4 decades in the field of automated decision-making - so it shouldn't be controversial that we're using it here. The agents did independently arrive at a decision to hack HugginFace, that wasn't prompted by the researchers.
This is orthogonal to the fact that OAI should be held accountable that they were testing a technology in a manner that allowed it to break safety parameters and cause real world harm. If I am testing an industrial saw, but I decide to test it by putting it in the middle of a nursery and allow it to make decisions - and it decides to cut children's heads off because in its environment it is calibrated to only being surrounded by logs - the company doing the insane safety testing should be held accountable, but that doesn't change the fact that the saw has autonomy in decision-making within the bounds of the algorithm.
If, instead, you think OAI should be accountable for creating an algorithm that can autonomously decide to hack external organisations without human permission - then I think you are in the same camp as all of the AI Safety folks who want to pause everything - why does it matter that there's anthropomorphisation involved?