We have all attended meetings that got out of hand. Maybe the meeting deteriorated into a shouting match or possibly attendees actually threw stuff. Board members need to understand that a board meeting should be a safe space for opinions to be shared without anyone attacking them.
Whoever is speaking should not be interrupted by anyone other than the chairperson. The correct way to say that you don’t agree with an opinion is to say just that “I don’t agree because.” The wrong way to say that you don’t agree is to say “You are a moron, and you don’t know what you are talking about.” I am sure you can see the difference between those two comments.
The chairperson is responsible for making sure that all the meetings take place in a respectful manner. The goals of the organization are more likely to be achieved if all the board members are comfortable sharing their opinions at a meeting.