One can feel the heat of the flames of this subject over here in UK. As an outsider in this topic I do realy feel that as quoted above those on the ground at the scane have to make a decision with vision that is less than those who after the event are blessed with perfect vision. This idea brings to mind the training and equipment at the disposal of the EMS crews. I would have to expect not only a suitable twin engined helicopter but also that the crew is fully trained in the use of NVG and have an IR and know every landing site that is likely to be used. The latter is an almost impossibility due to likelihood of the pick-up location being virtually anywhere though hospital sites should provide no problems. The final decision should rest with the crew who should have very tight guidelines encompassing such limits as weather and location unfamiliarity. The stupid American logic of 'Sue the Bastards' is an inherent problem which has grown up within the 'Gun Ho' attitude of the American brain.
A better logic would be the health and safety of the crew being balanced by the benefit of patient rescue.
Interesting to see that An AS350 was used to take a patient flying in Canada. Single engine in possibly urban area, oh no!