Tott,
I would begin to think "internal" pressures are even stronger than external....knowing the independent nature of most helicopter pilots. When you find a cure for both "internal and external" pressures...I bet we got it whipped!
When you consider most of these decisons are made at remote locations by a pilot that does not have access to...or is directly confronted by someone at the time the decision is being made. The guy may know that every decision to reject a flight is reviewed and unless there is a complaint, those that are accepted are never challenged. He may know there has been talk of closing the program if flight stats don't pick up...and the like. Thus that perceived pressure even if not overtly directed may be felt internally. Combine that with the fact it may be a child out there hurt....or something similar....it is hard to make a cold blooded decision sometimes.