In the vast majority of cases, rational thought has little to do with decision-making at such times, regardless of how much medical information is provided.  The internal processing (emotional, cognitive) of it all takes a great deal of time and a complete reversal of position from sustaining life, to ending it.  You sound like you have (and your husband had) a great capacity for rational, evaluative thought in crisis situations: but that is rare and not the standard to be used for many.