Bava Kamma, Chapter 8, Mishnah 5. We return to the topic of "kim lei bederabbah mineih," and let us recall the essence of the rule: a person who committed an act that carries a potential liability for court-imposed capital punishment - even if the court is not actually going to execute him, whether because there were no witnesses or because it was done unintentionally - this does not change anything. From the moment that, in principle, a capital offense is on the table, we do not obligate monetary payments incurred at the exact same time that the capital offense itself was committed.
The Mishnah brings two examples of this rule:
One who strikes his father or his mother:
"Hamakkeh aviv ve'imo ve'asah bahen chavurah" - One who strikes his father or his mother and causes them a wound and bleeding, has by the very act of drawing blood from his parents committed an offense punishable by death. It makes no difference whether the punishment will actually be carried out; it is enough that the offense is severe enough that under the right conditions it carries the death penalty, and therefore he is exempt from the five payments by virtue of this rule.
One who injures his fellow on Shabbos:
"Vechovel bachaveiro beShabbos" - Here too, one who injures his fellow on Shabbos and causes him to bleed, drawing blood on Shabbos is prohibited by the Torah, as a subcategory of the melachah of slaughtering, and under the right circumstances it has the potential for the death penalty. Therefore, one who injures on Shabbos and draws blood is not liable for the five payments.
And regarding both cases the Mishnah says: "Patur mikkullan" - he is exempt from all of them, meaning from all five payments, "mipnei shehu naddon benafsho" - because one who commits this offense, by drawing blood from his parents or injuring his fellow on Shabbos, becomes liable for things that are much more severe, at the very least at the hands of Heaven.
One who injures his Canaanite slave:
"Vechovel be'eved kena'ani shelo" - This is a new case, and in it the Mishnah establishes that the owner is "patur mikkullan" - exempt from all of them, meaning exempt from the five payments. The reason for this is different: any payment that would be due to the slave would automatically return to the owner, because economically the slave is like a conduit - anything he collects, produces, earns, lifts, or finds automatically flows to his owner. It turns out there is no payment here at all, since the owner would just be transferring money from one of his pockets to his other pocket.
It is worth noting that there are injuries where, if the owner takes out his slave's eye or tooth or any other of the tips of his limbs - such as the fingertips and the tip of the nose and the like - he is obligated to set his slave free. However, the subject of our Mishnah here is exclusively the five payments for injuries, and these payments do not apply at all when one injures his slave.