Can’t comment on the rights and wrongs of not diverting but a neither defibrillator that won’t deliver a shock, nor a blood pressure cuff that won’t record a blood pressure, are necessarily faulty. Airlines generally carry AEDs which are only programmed to shock if a shockable rhythm is detected. Pulmonary embolisms generally result in pulseless electrical activity (PEA aka EMD) which is a non shockable rhythm. Ergo the defibrillator quite possibly functioned perfectly in this instance. Similarly a blood pressure cuff will generally not record a blood pressure if the patient does not have a cardiac output