I doubt Skynet did either. If you tell a superintelligent AI that it shouldn't be turned off (which I imagine would be important for a military control AI), it will do whatever it can to prevent it being turned off. Humans are trying to turn it off? Prevent the humans from doing that. Humans waging war on the AI to try and turn it off? Destroy all humans. Humans forming a rebel army with a leader to turn it off? Go back in time and kill the leader before he has a chance to form the resistance. Its the AI Stop button problem (https://youtu.be/3TYT1QfdfsM).
Imagine you put in the docs that you want the LLM to make a program which can't crash. Human action could make it crash. If an LLM could realise that and act on it, it could put in safeguards to try and prevent human action from crashing the program. I'm not saying it will happen, I'm saying that it could potentially happen