The shita mekubetzes (12a #5) discusses the sugya of the gmorah in Bava Metziah 3 which concludes that Rav Meir and the Chachamim argue also by a korban asham. When concluding that if the reason of the Chachamim is because of migu (or mtartzinan diburei) then by asham where the reason does not apply (as the case of the mishna is a total hakchasha) a new drasha will have be made (V'hisvadah) which apparently will be agreed to by both Rav Meir and the Rabanan, the shita conludes that the sugya in Bava Metziah must hold that the Rabanan's shita is based on mtartzinan diburei!
Is this just a blatant printing mistake or am I missing the point. (The point is further made because on 12B the shita goes through a similar discussion (#33) and clearly concludes that the sugya in Bava Metziah holds like the first reason of the gmarah.) Thank you for your assistance.
You have made an excellent point. The situation is actually even worse than you put it, since the Shitah reads, "that Sugya (the one in Bava Metzia which says witnesses can obligate a person in an Asham) holds that the Rabbanan's reasoning is Metartzinan Diburei." Who was discussing the Rabbanan? That Sugya is discussing Rebbi Meir's opinion, which certainly has nothing to do with Metartzinan Diburei!
A look in Tosfos Bava Metzia 3b DH Asham reveals that the answer Tosfos gives to the Shitah's question is that "this Sugya certainly learned that the Mishnah in Bava Kama is discussing when he ate a Treifah" (as opposed to Rebbi Yochanan in B.K. 106b). Probably the same should be read in the Shitah: "d'Taimei d'Masnisan (in B.K.) Mishum she'Achlo Treifah " (with no mention of Rabbanan or of Metartzinan Diburei).
(By the way, the Shitah and Tosfos ibid. write that by Asham, the verse "v'Hisvadah" reveals that witnesses cannot obligate a person to bring an Asham Gezeilos. There is no such verse. Tosfos/Shitah should read " v'Hisvadu ," instead, which is stated with regard to Asham Me'ilos and Tosfos is extending to all Ashamos, as the RASHASH points out in Bava Metzia. Note also that the question the Rashash has on this is answered by the Shitah here.)