When I was on the condo board there were always a couple of owners who gave us a really hard time at the AGM. So we hired a condo lawyer to attend each subsequent AGM. It is worth the money to do so and he is still there on a regular basis.
The worst situation I have heard of was several years ago in our city when a condo owner knifed a condo management rep following a meeting.
It is a tough way to make a living. You can choose tenants for your properties but not choose the owners in a property you manage. Not for faint of heart but is doable if you are so inclined.