What is the ruling if the injured party amputates a digit to prevent spread, and the wound does not heal, leading to the injured party's death?

Primary text

If the injured party amputates the digit fearing spread, but the wound does not heal and the injured party dies as a result, the perpetrator is considered a partner in his own demise. Two possibilities arise: that Qisas must be exacted, or that Qisas is not due at all because the injured party's action was intended for self-preservation (necessity), constituting an intentional error (*amdu al-khata'*). In the latter case, the perpetrator owes half the blood money (*diyah*).