The Aruch Hashulchan (EH 13) writes someone who disagrees with Chazal on scientific matters, testifies about himself that he does not believe in Torah she bal peh, even though he would be embarrassed to admit it outright.
Of course, that’s assuming that every word of “Torah SheB’Al Peh” that we have today came from Sinai and was transmitted down to the Chazal without error or deviation… but that’s another argument for another day. 🙂
The Wolf