how do you know they had blue skies and were in fact VMC?
I guess we don't - but they said they were, and there was apparently photographic evidence. Make of that what you will.
Evidence is that crews were observed operating in and out of cloud, though telling McMurdo they were VMC.
Reference please?
We know that some certainly didn't operate VMC, though claiming they were
You don't know this at all (what is it bout the Mahon camp that makes them feel they have carte blanche to decide what is "known"??)
The fact that they arrived home is not testament to what did, or what didn't, transpire in the conduct of those flights.
Tell that to every person on TE901 who wasn't lucky enough to be on one of those flights instead of 28 Nov' 79.
All that does is heighten the fact that that none of those crews had any idea where the waypoint resided.
Which is not a major issue, because at the end of the day it doesn't really matter where a high altitude waypoint is. As is evidenced by the fact that there was no outcry after Capt. Simpson's flight.