Cazatou
<<Of course it is possible that the disparate altimeter subscale settings may have caused some confusion during the final desperate escape manouvre. >>
You described the requirements for altimeter settings some time ago such that those as found were not appropriate by regulation, practice, or common sense for the en route part of a simple ferry flight, even at low level.
If you maintain that they were not doing anything special in the area of the Mull, then are you saying that they were incompetent regarding their setting and use of the altimeters?
I am surprised that no one else has replied to this post of yours in this regard.
I find it hard to believe that they would have been using altimeters inappropriately given their experience and ability.
I have explained in great detail a possible explanation for the altimeter settings as found – they were entirely appropriate for a landing or close pass to ground at the elevation of the landing area I have described.