I wonder if there is a statistic of engine failures on twins.
And, engine failure in a twin does not take away 50% of available power-in modern twins it is considerably less, for 30 seconds might be even almost the same as running both engines, as transmission limits kick in.
Since I had long discussions with Mike Melia (the man that reinvented Massachusetts police Air support unit after tragic engine failure on their AS-350), I am clear about single vs. twin - I just cannot accept to spend days and days within H-V betting my life on a single RR250.
I did a lot of work on that engine so I think I know a few things about it and I would bet my life to it only occasionally and briefly (as I did in my 15 years of flight ops duties). Singles are used in this job primarily because they are affordable - and risks of decreasing profit against risks of losing the company in the aftermath of an accident are the driving force, with option of having an accident felt remote enough to be pushed aside. The tragedy of loss of life is not in the books/numbers. Only when it is experienced from up close and personal, minds sometimes change. Been there, seen that.