Is a slave who kills another slave subject to retaliation (qisas) if he is manumitted afterward?

Primary text

If a slave kills another slave, and the killer is subsequently manumitted, the killer must be executed (qisas). This ruling also applies if a slave wounds another slave, and the injurer is freed before the wounded party dies from the injury. Retaliation becomes obligatory because it was established at the time of the initial injury, which is the cause, and subsequent manumission does not nullify an established right to qisas. Parity (takafu') existed at the time the offense occurred.