How stringent are the standards of accepting the testimony of those who testify that a woman's husband has died? There are advantages and disadvantages to being "lenient" and accepting one witness's account, for example, depending on whether complications develop later, like that testimony turning out to have been wrong. Which leads to a discussion about witnesses in general, and their reliability. Also, a beraita on the case of a prohibited woman... With possible cases including kohanim, of course, and testimony about the husband having died. There are times the decision will be stringent, of course, and the kohen would be forced to separate. Including what happens when new witnesses follow some time later and say that the husband is alive. That is, no malice, but conflicting accounts, especially over time. Plus, establishing the testimony of women against that of men.