On daf 66b, the braiysa darshens ITI: V"AFILU B"SHABBOS. The gemorah asks how their would be a violation on Shabbos by sending out the goat. The gemorah answers that in the event that the goat become ill, the sender would be allowed to carry it on Shabbos. What about R' Nosson who is of the opinion CHAI NOSEI ES ATZMO PATUR? Answers the gemorah that R' Nosson would agree that if the goat were ill, one would be CHAYAV for carrying the goat.
1. Could the gemorah not have answered T'CHUMIM ALIBA D'RABI AKIVA? Although one could simply answer that the gemorah wishes to have the braiysa conform according to all.
2. Rashi and Tosfos discuss in Maseches Shabbos 94a why CHAI NOSEI ES ATZMO PATUR. Rashi explains that the live animal (or person) supports his own weight and lightens the load. Tosfos disagrees with Rashi and explains that one is PATUR due to the fact that in the Mishkan Nobody carried live animals.
According to Rashi, the gemorah's answer makes sense, once the animal is sick, it can no longer support it's own weight, and even R' Nosson would agree that you would be CHAYAV. But according to Tosfos, what difference would it make whether the animal is healthy or not, bottom line, is that this action was not performed in the Mishkan and should still be PATUR?
Ben Sugerman, Boca Raton, FL
1. Our Gemara would even be problematic according to the opinion of R. Akiva. R. Akiva only holds a person transgresses the Isur d'Oraisa of Techumim for walking a distance of 12 mil. The only Tana that holds the distance between Yerushalayim and the cliff that the Se'ir ha'Mishtalayach was thrown off was 12 mil, is R. Meir. However, R. Meir also holds in Meseches Eruvin (57a) that we don't start counting the 12 mil of the Techum from the wall of the city, but rather seventy and two-thirds amos later. This being the case, even R. Akiva would agree that the Ish Iti would not transgress the Isur d'Oraisa of Techumim, and the Gemara must conclude the Isur to be the Isur of Hotza'ah.
2. Tosfos in Shabbos (DH sheha'Chai) says the reason for the exemption of "Chai Nosei Es Atzmo", is because in the Mishkan they would not carry live animals. He explains that there was no need to carry them because the Techashim and Alim would walk on their own legs. One can presume that if the Techashim or Alim had been sick and unable to walk unsupported, the Kohanim would indeed have carried them.