AnFI,
We don't disagree by much but we clearly have a different view about night. My opinion is based upon over 10 years of police flying with a lot of night myself, and knowledge of a lot more by other police pilots. Inadvertent IMC at night in that group happens quite regularly (not often but regularly). Some such events are recorded in the system, but I believe most are unrecorded.
The police pilots are not permitted to fly IMC intentionally (for various reasons but mainly cos the operators with one exception don't want to pay for IR training and currency). However, many police pilots are or were IR'd (or the mil equivalent) and they fly stabilised and largely IFR equipped helicopters. Inadvertent IMC in those circs is likely to have a successful outcome.
There have been one or 2 notable "night into IMC" accidents in police flying, but the probability of survival is MUCH greater than the class of hele and operation we are considering here.
My view based on this evidence is that sometimes at night a pilot cannot see the IMC coming.
What evidence do you use to form your opinion?