Yes, they very often divide the points equally, but if one uses this with any
regularity, the altruism tends to drop away if someone is not doing his or
her fair share of the work.
I have never had to mediate a disagreement about this. If I had to I would
merely keep the group after class and be as unobtrusive as possible as they
continued to negotiate. I do try to keep the point values relatively low to
prevent massive conflicts. Try it! They really love to be empowered!