rov - birur or hanhaga; probable truth vs. certainty

Last post I mentioned the position of the Terumas haDeshen that rov is just a hanhaga and not a birur; that is, rov just points us to a probable solution to a dilemma, but does not resolve with certainty the underlying question. It would seem, therefore, that if we could achieve certainty, we could no longer rely on the probabilistic resolution of rov. For example, if I had a mix of 9 frogs and 1 tamei sheretz and accidentally touched one animal from the mix, given no other information, since there is a 90% probability that I touched a frog and not the one tamei sheretz, rov dicatates that I am tahor. But let’s say I could know with certainty which animal I touched. Let’s say a Navi came and revealed prophetically that it was the sheretz and not a frog that I came in contact with – would I have a right to still rely on rov? It would seem not, as an assumption about what probably happened cannot trump the revelation of what factually occurred, the certainty of truth.

The problem is that this thesis seems to contradict a well known gemara. The gemara (Bava Metziya 59) tells us about a dispute between R’ Eliezer and the Chachamim regarding whether a certain type of oven was tahor or tamei. R’ Eliezer marshaled all types of miraculous signs to prove that truth was on his side, culminating in a prophetic bas kol declaring from Heaven that his position was correct. Yet, the Chachamim stood their ground, rejected the bas kol, and declared the halacha always follows the majority opinion - “Acharei rabim l’hatos”, rov always wins. Based on the analysis above, this gemara is puzzling. Rov is probabilistic truth, but not factual certainty. Given no other information, we would assume the majority opinion is correct, just like in the absence of other information we assume a person touched one of the 9 frogs and not the 1 sheretz in a pile. But if we have a window on certainty, then that should trump rov. Just like a revelation of a Navi that factually the sheretz was touched and not a frog renders any discussion of what probably happened moot, the prophetic revelation of by the bas kol that R’ Eliezer is right should render any discussion of majority vs. minority moot.

Why is this case of tanir shel achna’i, the debate between R’ Eliezer and Chachamim, different than the case of 9 frogs and one sheretz?

(A similar question appears in Koveitz Divrei Sofrim of R’ Elchanan, and I think there is more than one way to skin this cat. I like the kashe so I figured I would share it to give you some oneg Shabbos.)