Rashi says that stam at a time of shalom, we assume it means a natural death (al mitaso) while milchama bolam, we assume she means mes bmilchama. The question is: isn't there drisha vchakira? Why doesn't bais din simply ask her to clarify what she means when she said "mes."
Yaakov Siegel, miami,usa
The Gemara (below 122b) cites a dispute between Rabbi Tarfon and Rabbi Akiva. R. Akiva maintains that one does not do Derishah and Chakirah of the witnesses whilst R. Tarfon maintains that one does. The Shulchan Aruch EH 17:21 rules that one does not do Derishah and Chakirah and Rema cites Rambam that it is forbidden to interrogate the witnesses a lot. Beis Shmuel #65 explains that one must not be too particular on the testimony for Agunah and every Rabbi should look for ways to permit a deserted woman to remarry.
However Rambam Hilchos Gerushin 13:15 writes that if the witness said that "so-and-so died and I saw him die", we ask him "how did you see him, and how do you know that he died?" and he is only believed if he testified that he certainly died but not if he merely saw evidence through which a majority of people would die. The Magid Mishneh writes that Rambam derived this Din from Gemara (below 122b) that R. Tarfon asked the witnesses detailed question 2 or 3 times and only then allowed the wife to remarry. Even though the Halacah is that one does not perform Derishah (i.e. interrogating him repeatedly to try and catch him out) and Chakirah (i.e. interrogating concerning on what day and at what time) nevertheless one must at least ask the witness what he saw.
In summary one should not interrogate the witness thoroughly but one should ask them what they saw. Therefore, because of your question, the Chelkas Mechokek (EH 17:97) writes that indeed there are no major ramifications from what Rashi 115a DH de'I writes that in peace-time "Mes" usually means on his bed while in war-time "Mes" means in the fighting, because anyway one must always ask the wife the reason for her husband's death.
However see Pischei Teshuvah EH 17:34 in the name of the Beis Meir who challenges the Chelkas Mechokek and writes that it is only necessary to ask the witness how he saw the corpse and how he knew about it, while in contrast when the wife herself testifies in peace time one is not required to ask her how her husband died (this is presumably because the wife herself is afraid of the complications she might encounter and therefore only testifies if she is sure). The Beis Meir writes that this explains why he never saw or heard of a case where a husband and wife went overseas and afterwards she returned home on her own and tells everyone that she is a widow, that the Beis Din ever require that she should testify in front of them, to say "My husband died. Give me a Heter". This is because in peacetime one need not ask her any questions.
Kesivah u'Chasimah Tovah