BOAC
I think I understand your frustration..........it works both ways!
It appears that in all probability, part of the Mull was visible at WPT change. That, I think, is a 'reasonable' assumption from the evidence.We know it continued towards the Mull and crashed in cloud. The gap here is what happened between those two events. It could have been 'gross negligence' indeed, but it cannot be proved beyond reasonable doubt. That was the requirement for judgement. It was not followed.
The moot point is "what happened between these two events" - with no evidence to the contrary
I think, is a 'reasonable' assumption from the evidence
that nothing happened. They just made a fatal error of judgement.
Further
and was there sufficient proof of deliberate action
- No - but does there have to be? In-action is more likely on the evidence. No one does this sort of thing on purpose