I think Michael believed that mister was going to kill them because he probably figured he was just going through PTSD. Mister also had red broom sticks strapped to him waist as if they were dynamite.  Michael probably also thought mister was not going to kill the lawyers because it seemed mister wanted the lawyers to admit to how much they get paid a year, and how much they give or gave to the homeless shelters. Mister was also most likely going through PTSD at the time of the incident, Michael   also did not think mister out to be a bad guy. Personal I feel mister just wanted sympathy for the homeless, and the unfortunate well being others, but for mister to attack rich innocent people is a matter that should not be addressed in such way mister addressed the situation. I don’t feel attacking rich people is the right way to handle his situation. Doing such had outcomes that were not going to go well for mister. Because of his actions he’s pay in the most tragic way possible.