the forecast required that the flight be planned to fly in accordance with IFR in the vicinity of the Mull.
Nice idea K52 but impossible due to the lack of icing clearance for the Mk 2 Chinook.
Instead, the crew were faced with a 'VFR or nothing' transit. Lack of a decent forecast never prevented SH crews form quite legally having a go. Provided that VMC was maintained, then there is nothing wrong with that. If the SH force was grounded by every poor forecast then they would rarely fly. It was only a forecast after all.
That transit, Walter, would require that the crew flew in accordance with VFR, in VMC and no other than visual contact would be legal for use in terrain avoidance, so the DME is not relevant.
What subsequently caused the crash would have to be proven beyond any doubt whatsoever in order to find the pilots guilty of gross negligence.
The fact that that has not been done is why we are still here ten years on fighting for justice.
I'll be away on 2nd June, but my thoughts will be with those who perished on that day, as they were this morning, when leaving BFS with the Mull in sight.