GLSNightPilot:
As always you present a logical argument but the likelihood of two pilot operations in a single engine helicopter is quite small and, because it would not be within the normal scope would likely suffer from CRM problems (which have been seen even in two crew helicopter operations).
However, I have to take issue with your contention that “deaths from exposure are non existent”; almost within the last two years (On February 16, 2003) there was a ditching in the GOM that resulted in the death of two of the occupants - which occured following a successful escape from the helicopter.