Comment by adriand

It sounds to me like you were driven more by other emotions — perhaps feelings of care, concern or worry. That doesn't prove that anger is useless, simply that in that situation, it wasn't the primary emotion you were experiencing or that drove your behaviour.

But let's suppose that the same situation unfolded, except you were Black, and the treatment you received by the legal system was rude and dismissive in ways that you were familiar with, having experienced racism many times before. In that situation you might experience much more anger, and you might rely on that anger to give you the courage and energy to deal with the injustice you were experiencing.