Furia, by now you ought to have figured out that HEMS in the USA is nothing like HEMS in Europe.
Also, JAR OPS3 are not quite as permissive as the FARs when it comes to performance requirements for helicopters in determined types of use.
Come to think of it the FARs do not set any minimum standards for performance except for IFR in a twin.
That is why we still fly singles off-shore and singles at night in EMS and over congested areas.
PC1 here in the States is a huge scarecrow, and all operators are doing their darn best to stave away (read lubricating the FAA) the ghost of the JARs.
The lax attitude and tolerance demonstrated by the FAA towards HEMS is also why some programs still manage to fly VFR at night without the use of aids to vision notwithstanding rules set forth in 135.207.