"Assume that you would have to carry out an operation meaning that you would use an aircarft to fly a person from A to B.
Given an identical route with exactly the same conditions (wx, technical maint., pilot exper.), - which type of operation would give the highest risk exposure of say a R22 helicopter or a Cessna 172 fixed-wing. "
I would take the R-22!
If the weather turns !!!!ty, you can land anywhere.
If you get inflight fire, you can be on the ground in seconds.
If you have engine failure, you only need space big enough for the rotor to autorotate and land.
I personally would feel much safer in the helicopter if doing a A to B transport.