MOD seem quite clear (the rules after all are their rules) that a helicopter flying below 140 knots airspeed requires the aircraft to remain clear of cloud, in sight of the ground or water and with a forward visibility of at least 1000 metres.
And that is exactly how the flight was being conducted.
The weather below cloud was not a problem, as Mr Holbrook's evidence confirms. Those on the Mull and in cloud can have no idea what the weather was like out to sea.
So at waypoint change I would suggest all was normal, or they would not have made it. What happened next to cause a turn in the wrong direction and a climb into cloud in the full knowledge that a climb to MSA was impossible due to the pathetic iceing clearance, no one will ever know.
The negligence occurred long before waypoint change. It occurred in a MOD office when someone thought it a good idea to release an aircraft into service when even Boscombe Down would not fly it.