A low experience crew in a new, unfamiliar type of helicopter coupled with weather that was probably close to, or beyond even IFR limits. I doubt they had yet learned to take full advantage of the IFR capabilities of the aircraft in any case.
In the past I had to reluctantly turn down a small number of mission requests because I was experienced enough to know that they couldn’t be safely flown due to weather. In one particular instance I was seriously taken to task over my decision. A very senior police officer try to make a big deal out of it and made threats about my continued employment. He apparently then tried to call out two other helicopter units including RAFSAR who also refused to launch, for exactly the same reasons (heavy snow, strong winds and fog). On that occasion the allegedly missing people were not actually in distress at all and didn’t need rescuing, they had planned and were equipped to stay out overnight if needed and returned home unaware.