Winch-control
So you confirm that the crew with the inexperienced Captain was the Primary Crew for the VIP task; whilst the experienced crew flew the routine in-Theatre resupply sorties? That does seem a rather odd way of utilising ones assets to their full potential.
It also means that crew of ZD576 had already been on the go for some 10 hours when they departed Aldergrove utilising someone else's Flight Plan with poor weather forecast on route. Moreover, it is unlikely that Flt Lt's Cook and Tapper had sufficient time to check the prepared flight charts thoroughly prior to departure; if they had they would have discovered that the turning point at the Mull was not. the lighthouse.
You say that this was SF "doing the job". It was exactly the opposite -"doing the job" would have entailed proper crew allocation in respect of the tasks to hand - not what suited crew members on that day. It would have matched crews to the tasks; not to their personal preferences.
The way this detatchment was run - it was an accident waiting to happen. The best that could be hoped for was that it would happen without fatalities; sadly that was not to be.