If he performed regular kosher slaughter of the bird with a knife and offered it up - he is, contrary to the expectations, liable, because of an additional phrase "or who will slaughter."
We thus find that what makes the bird a valid sacrifice (melikah) inside makes one not liable if done outside, and what makes one liable (shechitah, or kosher slaughter) outside makes one not liable if done inside.
Art: Perrault Leon Jean Basile - The Bird Charmer 1873
A page of Talmud in your inbox every morning — subscribe: https://talmudilluminated.com/subscribe/
