What is the ruling on the prayer of one whose 'awrah became uncovered during the prayer without his knowledge?

If a Muslim prays with his awrah (private parts) covered from the front and sides, it does not harm his prayer if someone views it from below, even if he is on the edge of a roof and someone looking up from below sees it; his prayer is valid. This is the opinion of the majority of scholars from the Shafi'i and Hanbali schools. However, a woman's feet are considered awrah by the majority of scholars, and she must cover them in prayer and outside of it. If they become uncovered, her prayer is not invalidated according to the majority. It is obligatory to lower the gaze from awrah.