In your book, Forgiveness Is a Choice, you talk about the psychological defense mechanisms. You say, in one part, that we use the defense mechanisms to hide anger from ourselves. Yet, is it possible that anger itself is a defense mechanism against disappointment or embarrassment?
Yes, you make a good point. Anger, indeed, can be a defense mechanism in the form of displacement. A person displaces an emotion onto another so that the real issue remains hidden. So, the psychological defense of denial can mask anger; displacement of anger can mask disappointment or embarrassment, as you say. Both anger and disappointment may need to be addressed in the same person.
Read more about defense mechanisms in Forgiveness Is a Choice.