I cannot agree more with the idea that the accident rate is TOO HIGH.
However on the article mentioned above they make too much enphasis on the use of NVG while we all know that the main cause of accidents in EMS either night or day is unintended flight into IMC conditions.
I believe that all pilost flying by night must have a current IFR ticket and if possible all HEMS ops during night time should be made with 2 pilots so if you encounter IMC condiions one of them that should be focusing on instruments all the flight should take control of the aircraft and inmediately gain altitude above the MSA of the area.
Helicopters for such operations must be fully IFR and must be adequately equiped with appropiate technology to lower the workload imposed on a HEMS crew flying by night and that encounters inadverted IMC conditions.
Operators must train regularly their crew to face the nightmare posibility of encountering IMC conditions by night at low leve and must make sure all crews are trained to transition safely into IFR.
Of course this also implies properly trained dispatchers that know what icing conditions are so no night flights are performed if marginal weather conditions are present along a low freezing level.
NVG are a very big help but will not navigate IFR through the clouds. They are better for obstacle avoidance and for take off and landing operations.
However the only way to avoid the too common accident involving inadverted IMC is a proper and safe transition to IFR.