59b middle
The gemoro says that if one is nivaloh by an animal shelo kedarko, then they are kosher for a kohen godol, because theres no zenus by an animal. But if it was done kedarko, then it would be toleh if you hold a kohen godol is allowed to marry a mukas etz.
Later the gemoro says the same thing, but this time, rashi explains this is only if you hold that mukas etz is kosher, meaning that rashi is explaining this bioh is kedarkoh.
But the gemoro brings a story to prove thus point from a wild dog and a cleaning girl- meachoreho, dehaynu shelo kedarkoh??
Avrumi Hersh, London england
Thank you for this excellent question! It is such a good question that the Ritva proves from your question that Rashi is incorrect when he says that Rav Ashi -- who said Niv'alah k'Darka Kesherah -- is talking about even Bi'ah k'Darkah. The Ritva therefore says that Rav Ashi is talking about Bi'ah she'Lo k'Darka, and the story Rav Dimi brought is a just as Rav Ashi said.
It seems from the Rashba that if we say that Rav Ashi is talking about Bi'ah k'Darkah and still holds that she is permitted to a Kohen as a Mukas Etz, Rav Ashi is following the view of a Tana in Nida (8b), but the Tana in our sugya holds that Mukas Etz is prohibited to a Kohen Gadol (this depends on the different Girsa'os in our Mishnah). Accordingly, we may say that Rav Dimi comes to disagree with Rav Ashi and brings the story to make a point that just Bi'ah she'Lo k'Darkah is permitted.
Kol Tuv,
Aharon Steiner