Helicomparator - you're right the assessment should be based upon the risks.
Unfortunately the risks associated with probing a high pressure reservoir, getting the stuff onboard, separating it and stuffing it down a pipe are on a well designed installation (there are a few) pretty close in round terms to the risks of getting to and from it for the people who work there.
For the pilots who fly them to and from the risks are actually significantly higher.....
For risks I'm talking about the individuals risk of death per annum, whilst undertaking their normal rotas.
For Mighty Gem - the chances of an engine failure during that critical period of flight are actually more of less equal to the rest of the entire flight (if it is under an hour). Big power changes are very likely to cause issues. Hence the need to fly profiles which offer a chance of recovery.
The major disappointment for me is that all of the 'newer' designs which are used offshore in the UK have had a variety of issues - which frankly should not have occured. From my personal perspective if you certify a helicopter on the basis of 10-9 failures per hour and it promptly fails then the certification should be pulled. For the 332 and 225 failures - I despair - designing reliable transmissions after all this time should not be so hard....