I was listening to the shiur and I was bothered by the following two questions. The conclusion of the shiur was that Reb Meir holds that למיעוטא חוששין, because he understands רוב to be a הנהגה דין. However if that’s the case so why by לקמן דאיתא רובא which the shiur stated everyone holds to be a הנהגה דין does everyone including Reb Meir hold that we are not למיעוטא חושש? its seems counter intuitive that by לקמן דליתא רובא that at least חכמים hold that it’s a בירור Reb Meir says למיעוטא חוששי because its הנהגה but לקמן דאיתא רובא that everyone holds to be a הנהגה דין everyone holds we are not למיעוטא חושש?

 Also if Reb Meir holds that both denim of רוב are הנהגה which is still not וודאי as evident in B”M 6B how does he explain the Parsha of mamzer which is based on the idea that רוב is וודאי as evident in end of forth Perek of Kidushin? I would so appreciate an explanation.