It is not that we ignore the injustice or explain it away. We cannot release someone from a debt unless we identify it.
Once we release the person, our emotions are more likely to catch up with our intention.
This, I think, is what the "Judge not" refers to. We are not to set ourselves up as judges who impose and execute sentences on those who have done wrong, especially against us. Not to judge does not mean not to name a sin, but not to make oneself the arbiter of justice--to take the place of God. Not to judge makes it a heck of a lot easier to be merciful to those who have sinned against us. Judge not lest you be judged by the same measure you have meted out justice. That's scary.