The S-76 is a very capable helicopter, particularly when properly equipped for IFR flight, to fly into IMC.
Perhaps this comment is a bit late but experience in forensic examinations and investigations has caused me to be a bit more circumspect when commenting on the operations of an aircraft by other PIC's and aircrew.
For whatever reasons, the civil operators of rotary-wing aircraft seem much more likely to ignore the lessons of military operators than is the case for operators of fixed-wing aircraft. This seems to occur in operations in weather at or approaching weather minimums as is reported to have existed on the date of this accident.
There are several existent hypotheses as to why accidents such as this one are now far more likely, on a per hour of operation, or in the totality of circumstances basis, to occur when civil operations of rotary-wing aircraft are compared to those of military operations. In this instance, I would suggest that "Human Factors" were more relevant to the end result than aircraft or systems failures. One of the first relevant factors is the perceived "need to go" attitude that owners seem to impress upon their aircrew members and the absence of any "intervening authority" that would support, or require that such a flight (or mission) be scrubbed due to environmental conditions. Given the marginal meteorological conditions, and the variance in terrain altitudes and abrupt elevation changes it might be concluded that there was a question as to judgment in even attempting to conduct such a flight as was planned. S-VFR Clearances can become a trap for a PIC who is not both current and qualified for flight into IMC as the potential for inadvertent penetration of such conditions would almost be a probability rather than a possibility without due diligence and a willingness to avoid same and to RTB or remain clear of same, even should it require that the aircraft descend in VFR conditions pending the receipt of the appropriate IFR clearance to a suitable destination in lieu of continuing flight marginal conditions that could result in the need for radical, or emergent maneuvers to avoid penetrating into zero, or near-zero visibility, particularly if the precise position of the aircraft relative to abrupt elevation variances is not known at all times. Operating an aircraft in such (near, and/or actual instrument) meteorological conditions can consume near or absolute concentration of the PIC which may exceed their ability to remain cognizant of weather and obstacle avoidance while successfully maintaining absolute geographical integrity in navigation and concurrent attention to aircraft systems management and airframe operational limitations. The workload can exceed the capacity of a single pilot of such an aircraft almost instantaneously, well before they would be able to "see and avoid" hazards by virtue of time delays inherent in the rates of interpretation of even the most competent airman's mental and physical capabilities. The absence of an IFR-rated co-pilot, first officer or whatever term might be most applicable to such operations can represent the proximate cause of the failure of a single pilot to avoid such an accident as, at a minimum, the pilot not actually flying the aircraft while it was being operated under visual, or special-visual flight rules would be "flying inside the cockpit", e.g. monitoring the operational factors relative to the aircraft systems, ensuring that any maneuvering would not exceed the design-specifications for the airframe and concurrently backing up the operation of the aircraft by the operational pilot by remaining on instruments and prepared to advise him as to current position as can be determined by the navigational equipment and systems onboard, proximity to obstacles both natural and man-made and to be be prepared to assume control of the aircraft should it inadvertently incur IMC so as to preclude the necessity of the pilot then operating the airframe in VFR/VMC modality to virtually immediately translate into instrument flight control and management of flying profile.
I can say, having been an Operations Officer/Approving Authority in any number of military flight units over the years that as we learned the hard way the necessity of Risk Management using pre-flight Risk Assessment Protocols and the wisdom of simply not flying, or approving the operation of an aircraft under the meteorological conditions reported to exist at the time of departure, enroute and at the expected time of arrival at the destination landing site, and crewmember population aboard the accident aircraft. Perhaps it is the "undue influence" of the owner(s) of aircraft, and those who employ flight crews, and their failure to recognize the limitations of both airframe and those who operate it that create a predicate for such incidents, however, that does not relieve the PIC of responsibility of the operation of the aircraft and the acceptance of any, and all requested missions and mission profiles. I am not being hyper-idealistic, nor absolute in my belief that the aircrew responsible for the successful completion of the flight tasks can refuse to fly them without risk as to their future employment, however, civil aircraft operators and crew members should, along with those who design, manufacture and sell these aircraft begin to find a means of conveying to the owners of same the fact that despite the best of intentions these aircraft are not able to repeal the natural laws of flight and aerodynamics, and that notwithstanding the desires of all involved in their operations to meet each and every need of the purchaser/owner/responsible party there will inevitably come a time when the PIC will simply have to say to their employer the word "No", and insist that they find an alternative means of reaching their destination if time is of the essence and the flight cannot be delayed until more suitable conditions exist for its successful completion. Perhaps that might have been a better course of action if it were to have been practicable for the PIC of this aircraft to have said to Bryant, et.al., just take a limousine and travel on the roadways and if the weather clears up that he would just pick them up in the helicopter and fly them home.