In one of the Kinnot we say, we mention that nobody could persuade God to have mercy upon the Jews until He came to our foremother Rachel. Abraham, Isaac, Jacob- none of them could change God's mind. But when it came to Rachel, God threw out the scale of measurement and justice.
Why? Because Rachel had an unshakable argument. "I took my tzarah into my own house by giving Yaakov the signs when it was Leah who was with him," she said. "I thought I lost my future then. It had been apportioned that Leah was to be Esau's and I was to be Jacob's. Now Esau would be my lot. But I did it anyway."
R' Aaron Lopiansky explained that when one does this and is maavir al midosav, goes beyond that which is expected in such a way, there can be no judgement. God throws out the scale because Rachel herself threw out the scale in her actions.
During the Six Day War, when R' Lopiansky was in The Mir, the yeshiva was situated on a street where it was right near the Jordan border. Therefore, it was shelled. The bochurim shook in their basement/bunker and hoped that they would survive.
When the war was over and the Mir building and its yeshiva had remained intact, some of the students asked R' Chaim Shmulevitz (then the Rosh Yeshiva) in what merit they were saved. Was it because of the Torah learning? The fact that the students were kind to one another?
"No, it was none of these things," answered R' Shmulevitz. "Next to the Mir there lives a woman, a woman who is very bitter and griefstricken. The husband of her youth, who claimed to love her and who married her, walked out on her, leaving her an agunah. She had no children and she had no way to remarry. All those who saw her knew that she was an agunah, and worse, that she was one whose husband had left her deliberately. All her days, she walked around with this cloud of grief, bitterness, resentment and humiliation over her head. She was very unhappy.
"When the shelling started, she came to hide in the Mir bunker. She didn't have one of her own. And she said to God, 'God, I'm forgiving my husband now. And if I can forgive my husband, You can forgive us whatever each one of us has done so that we can live.' She's the one who saved the Mir Yeshiva."
When you are maavir al midoseich, when you throw out the scale, God has no choice but to do the same.