All those years of US Army UH-1's flying all over Germany IFR and other places. Fort Rucker, the Army Aviation School, hosts whole fleets of UH-1's and TH-57's (Bell 206's) that were dedicated to IFR training. Back in the old days, Bell TH-13T's were the workhorse (Bell 47's).
I guess the UK and Europe know better and have valid reasons for all of the requirements they laid down about routes, proving reliability of engines, etc.
For sure, the best way to keep the Accident Rate down is not to fly at all.
However did the Bristow 206 ever survive all those years doing IFR Training for hundreds of Bristow's Pilots as has been described by several Senior Bristow Pilots here.