This is now a pointless exchange Caz.
Just go back and read what has been covered before.
If the Board believed this flight was impossible to complete, without climb into the icing layer, they would severely criticise the crew for even attempting it.
They didn't. The sortie was possible to complete VFR (at least on forecast), by simply avoiding the Mull and flying around it.
If you have forgotten the difference between Forecast and Actual, do avoid further embarrassement and stop posting on the subject.