Tohoros 5:9-6:1

Tohoros 5:9

If a single witness tells a person that he has been rendered unclean but that person denies it, he remains clean. If two witnesses say that he has been rendered unclean and he denies it, Rabbi Meir rules him unclean but the Sages say that the person is believed about himself. If one witness says that a person has been rendered unclean but two say that he hasn’t, he remains clean regardless of whether the impurifying incident is alleged to have occurred in a private domain or in the public domain. If two witnesses say that a person has been rendered unclean and one says that he hasn’t, he is ruled unclean regardless of whether the impurifying incident is alleged to have occurred in a private domain or in the public domain. If one witness says that the person was rendered unclean and another says that he wasn’t, or if one woman says the person was rendered unclean and another says that he wasn’t, the person is ruled unclean if the impurifying incident is alleged to have occurred in a private domain, and clean if in the public domain.

Tohoros 6:1

Let’s say that a certain place was a private domain, it became a public domain and then reverted to a private domain. When it’s a private domain, doubt regarding impurity that arises in it is ruled unclean but any doubt regarding impurity that arose in it while it was a public domain is ruled clean. Let’s say that a critically ill person was taken from a private domain to a public domain and then back into a private domain. A doubt (regarding whether he was alive or dead) that arises in the private domain is ruled unclean, while a doubt that arises in the public domain is ruled clean. Rabbi Shimon says that the public domain intervenes (between the two private domains, i.e., if we assume the person to have been alive in the public domain, we can’t assume him to have been dead in the first public domain).