Is it true that a man who saves a woman from drowning becomes a mahram (a relative one may not marry) to her?

Question:
The questioner asks: If a man saves a woman from drowning, does she become his sister, such that it is not permissible for him to marry her and she becomes a mahram to him?

Answer:
This is a fatwa for the common people. This is what the common people embellish. No, he does not become a mahram to her. He does not become a mahram to her except through the legal causes of mahram status, such as lineage, breastfeeding, or marriage.