I don't agree with you stopdog because it's impossible to be that perfect all the time if they are honest about what they're feeling. But they don't have to tell the client they are angry if it's inappropriate. They certainly shouldn't yell or take revenge in any way. They should realize they were angry and then think about why they got angry so they know how to deal with it better next time. For example, once the therapist realizes he got angry, he could try to understand the client better so the therapist can be more patient next time and not get angry when the same situation comes up again.