'XXX' has it pretty much covered here:-)
'Biggles' obviously you mean well but are incorrect in some .of yr content as has been mentioned.
I've done around 3 or so Mercy Flts as there was no other option at the time that could be taken to complete the mission. The ONLY rules that where not complied with where duty hrs & the addition of another pilot which was needed on certain long duty timed flights, all other rules that involved safety directly such as A/C serviceability, fuel requirements, compliance with WX etc,crew ability/authority & Equip where never broken, anything else outside of those area's was willful disregard for life before you even launched the mission.
The main criteria was that the CP had to be informed & that all reasonable alternative possibilities where considered/exhausted BEFORE a Mecry Flt was undertaken & even then there was paper work for the Flt at the end of the mission.
It was taken lightly that's for sure!
There's a saying that we whom where involved at putting lives at risk to save others ........... "there's no point in killing 3 or 4 to save one, made sense to me, life preservation begins with ones self
Wmk2