Exercise balls are strange inventions. On one hand, if used correctly, they can be a great assist to those who cannot get to the gym or do not have access to the best equipment. They are affordable and versatile. The problem is, the people who get their hands on exercise balls never seem like they want to do the right thing with them (i.e. exercise).
It seems these people have not quite grasped the basic ideas of physics. In many instances, these folks got what the rest of us call a "life lesson". Do stupid things on camera for a laugh, you might get hurt. So as much as you may cringe or feel bad for them, there really is no need. If two people run at each other at full speed with a single exercise ball between them, they sorta deserve whatever happens next.