Specifically crying. There is no place in a debate for tears.
I've had this experience before, where a group is discussing a serious issue that raises the emotional level all around and someone bursts into tears. I tend to feel blackmailed by that. We all want to be considerate and respect that someone is profoundly emotionally affected by the debate, but not to the point of giving in to that person's position.
One group I was a part of got to the point of offering a few moments to the person to gather themselves back up before returning to the debate. Fascinating how quickly those tears dried up and how seldom they returned in later debates.