So how do you respond to unreasonable people? The first thing is to identify who is being unreasonable, and that may be easy to see since most of them display this characteristic on a regular basis. If you can, avoid them! If not, minimize your time and topics if you deal with them one on one. And if necessary, have a witness.
One of the keys to dealing with emergencies is planning and writing out a plan on how to deal with them. During the emergency is not the time to do the planning as we don’t do our best planning and thinking in stressful situations. The same type of plan needs to be thought through and chosen ahead of time on dealing with unreasonable people.