Mishnayos Kerisos Perek 5 Mishnah 3

Rabbi Akiva says: The statement of Rabbi Tarfon appears correct in the case of minimal misuse, but in a case where he is confronted with a case of uncertainty with regard to misuse valued at ten thousand dinars, would it not be preferable for him that he will now bring a provisional guilt offering valued at two sela and he will not bring payment now for uncertain misuse valued at ten thousand dinars? The mishna concludes: Apparently, Rabbi Akiva concedes to Rabbi Tarfon in the case of minimal misuse. He agrees that at the outset one brings payment for misuse and its additional payment of one-fifth, and conditionally brings a guilt offering. Apropos the previous case in which one brings the same type of animal when liability is certain as when liability is uncertain, this mishna teaches: With regard to a woman who brought a bird sin offering in a case of uncertainty whether she miscarried a fetus that would have rendered her liable to bring a sin offering or whether what she expelled would not render her liable to bring an offering, in which case this sin offering may not be eaten by priests, the halakha is as follows: If before the nape of the neck of the bird was pinched it became known to her that she certainly gave birth, i.e., miscarried, in a manner that obligates her to bring a sin offering, she should render the offering a definite sin offering, as from the same type of animal that she brings a sin offering for a case where it is known to her that she miscarried, she brings a sin offering for a case where it is unknown to her.