Responsa for Bava Kamma 83:15

תניא אידך בעל השור נקי ר"ע אומר נקי מדמי עבד

— R. Adda b. Ahabah therefore said: [You might have been inclined to think thus:] In the case of men where their purpose was to kill one another, even if mischief results to a woman, a civil liability<span class="x" onmousemove="('comment',' V. p. 238, n. 4. ');">¹³</span> will be imposed, whereas where they purposed to kill the woman herself [who was in fact killed], no civil liability<span class="x" onmousemove="('comment',' V. p. 238, n. 4. ');">¹³</span> would be imposed. In the case of oxen, however, even where their purpose was to kill the woman [who is indeed killed by them] a civil liability should be imposed for the embryo. [To prevent your reasoning thus] the Divine Law on another occasion purposely states, <i>'The owner of the ox shall be quit'</i> to indicate exemption [altogether in the case of oxen]. And so also R. Haggai upon returning from the South, came [to the College] and brought the teaching [of a Baraitha] with him stating the case in accordance with the interpretation given by R. Adda b. Ahabab. Another [Baraitha] teaches: <i>'The owner of the ox shall be quit'</i> [implies], according to the statement of R. Akiba, quit from compensating for [the killing of] a slave.<span class="x" onmousemove="('comment',' V. supra p. 232. ');">¹⁵</span>

Teshuvot Maharam