In this previous post we left off with comparing the Rambam, who holds that once an eid echad establishes that a piece of meat is cheilev a person can receive malkos for eating it, with Tosfos, who holds that a chiyuv misa cannot be predicated on an eid echad’s prior testimony that a woman’s husband is dead. Is this case identical to the cheilev case?
R’ Shimon Shkop argues that you can be mechaleik. The Torah gives ne’emanus to an eid echad to tell us whether meat is cheilev or kosher. According to Tosfos (Yevamos 88), the ability of woman to remarry based on the testimony of an eid echad is only a takanah derabbanan based on the combined factors of dayka u’minsiba, the fact that a woman would not remarry without verifying and being certain her first husband is dead, and the word of the eid echad (who otherwise would not be acceptable in a case of devar sheb’ervah). It's not that the Chachamim gave the eid echad ne’emanus – rather, the Chachamim said that despite the lack of ne’emanus which an eid echad has, a woman is still entitled to remarry to avoid an agunah situation. If at a later point that situation leads to a question of dinei nefashos, the fate of the first husband is still viewed as an unresolved issue.