System accountability is a hard topic for us. So here's how we view it:
You should take accountability if they do anything out of the body / outsys to anyone. However, if it is in the body / insys, then that one person is held accountable.
Why? Because you share a body and account(s). You have to take accountability for anything that anyone does outsys, however this doesn't mean you did it. You're just saying "I know what my headmate did was wrong and I apologize and will talk to my system about this along with them." While insys doesn't have to apply here. Because it's in the body; especially if you're separate from one another.
However, these two things are different from one another. No this doesn't mean you did do it if you didn't, you don't have to take the blame for it, however, you do have to accept you are living with likely multiple people in one body and if someone screws up, you all have to take the blame as unfortunate as it may be.
Rather, insys you are separate beings. I compare this to a society. If one does wrong, they take accountability for it. That's what it should be regarding insys.
Outsys, however, like I've said, you should take system accountability if they did anything to anyone or done anything outsys.