Is expiation obligatory for someone who swallowed saliva that remained in her mouth after removing pork she had tasted unknowingly, out of shyness from people?

The impurity and prohibition of pork are matters of necessity known to every Muslim. Disposing of the food upon realizing it contained pork was a good act, and we ask Allah to make this deed weigh in the balance of good deeds. What remained of the food in the mouth should have been spit out. Since that moment has passed, she should seek forgiveness and repent, and there is no expiation due upon her. Allah is more deserving of shyness than people.