(Pro 29:22 KJV) An angry man stirreth up strife, and a furious man aboundeth in transgression.
I don’t see any qualifiers on “angry” (639). We don’t see the source of it. We have no idea if it is righteous or not. Having said that we see how it is interpreted. It is sin.
How do we know that this anger is sin? Look at the target of the anger. It is stirring things up. It seems that it is multiplied in other behaviors. This is not the anger at injustice that makes you go on long walks and ponder on how you can work on a problem in your city. This is not the emotion that drives you to read your Bible more carefully to seek truth. This is a self centered lashing out for personal gratification.
So? What is the result of our response? When I get angry on the spur of the moment I tend to want to justify myself or win some points. That is certainly not in the category of righteous.