Black and white thinking sounds like a label that someone can use as a defense mechanism to get out of taking responsibility for their own actions. I know of someone who has made, not just one mistake or two, but has repeatedly made the SAME MISTAKE multiple times, over many years. The person never apologized either. They never owned up to their mistakes.
T hey are trying say MULTIPLE MISTAKES was just ONE MISTAKE. Sorry no can do.

To say that person is bad is not black and white thinking, they are bad and have proven it multiple times over. imo.