Demonstrations are just that, rehearsed sequence of movements. Free style, punches, kicks, locks, chokes and throws that you don't see coming or you do see, but require some immediate reaction is crucial to test a techniques real effectiveness. Yes sometimes a person will be hurt or injured. Perhaps wearing some protective gear if you have the fear factor will help decrease the risk of injury. Demonstrations isn't real fighting.
When you find any protective gear that will protect against broken wrists and dislocated elbows, please let me know.