BOAC
Well said - there was no evident intent to overfly the Mull - they rattle off as though deliberately trying to hide the significance of these conditions - these conditions would only have presented a problem if they had for whatever reason a need to approach directly as the presence of the landmass would have never been hidden but judgement of distance to it to a useful degree would have been impractical - and in which case they would only have attempted such at speed with a local reference giving them accurate range - hence the interest in the CPLS and their apparent deliberate approach to a known LZ.
Regarding your query about the up-slope mist - the phenomenon is described in wind-farm studies (Google "wind farm" & "speed-up") - once you are aware of it you can see it quite often - here you can see a layer of mist close to the ground where the flow is around as opposed to up.
Ailsa Craig, for the record (don't know who took it) - when moist air is pushed against a sloping/curving surface the layer next to that surface is compressed, it then speeds up, drops in pressure, cools, and so condensation can occur in that layer next the surface while not yet in the bulk of the air mass moving around/up that obstacle.