a degraded level of service is acceptable
He didn't say that, but it's probably inevitable. Just read the NPAS thread on UK Police Air Support.
how the air ambulances cope with their patients? Also how they justify EC135
HEMS: aircraft, small, because that's all they can afford. One patient, generally on a stretcher, usually in a stable condition(
AFAIK, I'm sure jayteeto will correct me), terrain and weather usually fairly benign(day vmc, non mountainous, overland).
SAR: often multiple casualties, various injuries needing attention, extreme weather and terrain(plus over water), long transits.
Obviously something a bit bigger needed.