I don't believe that ANY of the campaigners have any doubt (whatsoever!) that the hillside where the aircraft impacted was in IMC at the time of impact, nor that the lighthouse keeper was also standing in IMC, but the fact that the aircraft crashed whilst IMC does not mean that it had been deliberatley flown there.
It is very likely that the aircraft was under control when the Supertans waypoint was changed to a point further up the coast and very likely that this selection indicates that the crew had visual contact with the coastline at the time. What we don't know is why the aircraft did not subsequently turn the necessary few degrees to the left. A number of hypotheses have been put forward in an effort to explain what may have happened but, in the absence of ADR/CVR, we shall never know what DID happen. But we do not know, even 'beyond reasonable doubt' that the reason was the negligence of the crew.
The aircraft's supposed (high) groundspeed is used by Day/Wratten (+ JP et al) as evidence that the crew was already negligent by the time of the waypoint change, in that they were flying too fast for the conditions, but this logic is flawed. An alternative explanation is that, notwithstanding the fog at the crash site, conditions were so good that a high-speed cruise was considered by this highly-experienced crew to be entirely appropriate. Weight is lent to this possibilty (probability?) by Holbrook's evidence and by anecdotal evidence by many on this thread regarding typical orographic conditions (ie often clear conditions in close proximity to the hill fog) in the area.
The MoD could have heeded the findings of the various inquiries already held and reversed this extremely unfair finding of Gross Negligence against Tapper and Cook; this would have left everyone happy, as even Day/Wratten could have conceded that new arguments had come to light and that they had acted in good faith. Now, however, the whole ugly truth about lack of airworthiness has come out and others have been placed in the firing line - those who, in the face of the experts' advice, pushed the HC Mk2 into service in a pretty shameful state.
I agree that the names of the pilots can be cleared pretty quickly, but the new Government should not shrink from a thorough and independent inquiry into the circumstances surrounding the entry into Service of this immature aircraft and why, despite no actual evidence, messrs Wratten/Day came to their remarkable conclusion. Was it that they honestly believed that an aircraft impacting a fog-shrouded hill was proof of its crew's negligence, or might it have been a way of hiding the fog-shrouded evidence that some of their Air-ranking colleagues had pushed an immature aircraft into service?