What is the ruling if a witness retracts after the penalty or execution has already been carried out?

Primary text

If a witness retracts after the execution of a penalty or judgment, the ruling becomes equivalent to the ruling concerning the retraction of that single witness's confession (Iqrar). If the witness confessed to something necessitating Qisas (retaliation in kind), Qisas becomes obligatory upon that witness. If the witness confessed to something necessitating a heavy/aggravated blood money (Diyah Mughallazah), that witness is liable for their share of it. If the witness confessed to error, their share of the mitigated blood money (Diyah Mukhaffafah) becomes obligatory upon them.