Ok, so if you're in a group of 100 other people and they vote 99-1 to take all your money, it's group decision making?
These are tiny numbers, but yes. I am not saying it would be right, but it is what would happen. I am treating these as questions of what is, not what should be.
So, killing people by mass vote is a form of group decision making? Wouldn't not killing by discussion also be such? How do you know murder or theft is what would happen (what is)?
If people decide to kill then someone dies. I'm not really sure what you are asking. I dont know what would happen. Again, I am not talking about what should happen.
Speculating? Sure. I am not saying there literally is a group of 100 deciding to kill someone. You asked of a group who decided to kill could kill. I am saying yes.