Final answer:
The contraindication for implementing the Medical Termination of Resuscitation (TOR) protocol in a cardiac arrest is 'Unwitnessed collapse in an unresponsive patient' because the duration the patient has been without vital signs is uncertain.
Step-by-step explanation:
The scenario considered a contraindication for implementing the Medical Termination of Resuscitation (TOR) protocol during a cardiac arrest situation is c) Unwitnessed collapse in an unresponsive patient. When a patient collapses without witnesses, it is important not to assume that resuscitation efforts will be futile, as there is a chance that the patient has not been without a pulse or breathing for an extended period. In contrast, evidence of rigor mortis (a), absence of pulse and respiration (b), and sudden collapse with no pulse in a witnessed situation (d) do not necessarily contraindicate the initiation of the TOR protocol. Each case must be evaluated on its own merits, taking into account relevant factors such as do not resuscitate (DNR) orders, body temperature impacts on heart function, and the possibility of additional harm through untrained CPR application.