"The 427, another low-volume type, has a far better accident history than the Explorer (without the 20+ ADs related to the Explorer's VSCS, TT straps, etc.). So too, proportionately, does the EC135 (7X production volumes), and I suspect the Power/Grand (4X production volumes) do as well".
The 427, despite being basically a derivitive of every Bell design since the '60s, so hardly cutting-edge technology, (already being phased-out of production) has managed to garner itself 14 ADs despite having being around about 5 years less than the Explorer.
The 135 meanwhile, has scooped up a very commendable 40+ ADs in a similar time frame to the 902.
As for accident stats, can you really compare the record of a mainly VFR twin which is largely used for fair-weather private and charter work against any of the machines used for the much riskier tasks of HEMS / Police ops and get a meaningful outcome?