The gemara bottom of 33b:
Is the point that the shaliach (who apparently was just given the animal to shecht and sell without knowledge of its being a shor haniskal etc) was not chayav anything so his doing the Shechitah u'Mechirah does produce a Chalos. which then goes back to the Shole'ach and adds on the Tashlumim which he'd otherwise be Patur due to Kam Leih b'Rabah Mineih.
Tuvya Marcus , Jerusalem Israel
Shalom u'vrachah!
You'll forgive me if I review some parts of the discussion that may already be clear to you.
Initially, the Gemara thought that from the Beraisa's case of Shechitah, there was a proof that Rebbi Meir obligates payment even when the sinner commited a capital crime.
But this proof is rejected, since Rebbi Yochanan is cited as understanding that in the Beraisa it was not the thief who slaughtered the animal but rather the Shali'ach. So, it is the Shali'ach who is Chayav Misah, whereas the thief is Chayav to pay the Arba'ah v'Chamishah for Tavach u'Machar. (This is so, despite the general rule of Ein Shali'ach l'Devar Aveirah, since Tavach u'Machar is an exception to that rule, as Rava/Rebbi Yishamel/Chizkiyah expound.)
You wrote that the Shali'ach was given the animal to slaughter and sell. I assume you mean slaughter or sell (Shemos 21:37).
If I understood correctly, you indicated that the Shali'ach is unaware of any particular problem involved in slaughtering this specific animal. I don't see the reason for learning that way. If anything, his awareness of a capital sin makes the Chiyuv Misah more definitive (granted, if it is Shogeg, that is a Machlokes, discussed on Daf 34).
I am not sure what you mean by "produc[ing] a Chalos." As I believe you correctly expressed, according to Rebbi Yochanan, since the thief did not commit a capital crime, he therefore bears a Chiyuv to pay, from which he otherwise would be Patur due to "Kim Lei bed'Rabah Minei."
I hope this helps!
Best wishes,
Yishai Rasowsky