tried to ask a question of the kolel re rabbi yehoshua's two positions on chulin 58a wanted to know if the two positions he holds there are related, which came first.
If you look carefully, you will see that Rebbi Yehoshua made only one statement 'V'lad Tereifah Yikrav (le'Gabei Mizbe'ach)', and it is the Gemara which presents two different ways of explaining it. If he is speaking about where the animal became a Tereifah first, and pregnant afterwards, then his reason is because 'Zeh ve'Zeh Gorem, Mutar'.
Whereas if he is speaking where it became pregnant first and a Tereifah afterwards, then his reason is because 'Ubar La'av Yerech Imo'.
I think that this dispenses with both of your questions.
Be'Virchas Kol Tuv,
Eliezer Chrysler