This is how Author be taking responsibility problems like this in real life too. Just taking actions without thinking too much and just be done with it.
Even if you're angry because of what your mother had done to you, you should still pick your words wisely. Words can scar deeper than any visible scars. And Hyesung better not forget what his mother had done to him... he can forgive her but not in a way he'll act like nothing happened between them.
She's becoming more and more nothing but a rotten at this state, and annoying people can't even let her rest properly.