Notso, you don't need HF between Moscow and London.
Sure, we all know what the rules say about use of ATC (and company) frequencies for such matters. Provided that the frequency is relatively clear, I would have less trouble with people breaking that rule than I would with them listening to whatever they can find on the ADF.
Of course safety has to come first. You mention the famous Varig flight. You don't seem clear about the details, however. Both pilots were listening to the football commentary. When the "Pull Up" command came, one said "Shut up, Gringo" and disabled it. I don't know what your definition of "impeccably" is, but I hope you were being sarcastic. "Impeccable" that is not.
If ATC were too busy, or the flight crew were too busy, then tough. No results possible. They have a job to do, and that must come first.
Having said that, I would be extremely surprised if there wasn't a moment in the cruise when ATC was quiet and a polite enquiry could have been made. A large part of our job is to provide a service to the paying passengers, and just a little
PR goes a long way. No need to go overboard with it, just bear in mind that we want them to come back and use us again. If the captain on this particular flight felt it was below his dignity to demean himself with such mundane matters, then one hopes he will retire soon. If the problem was lack of time and attention to his primary duty, then it costs nothing to explain that in a friendly manner to the enquiring passenger when Rockhound asked on disembarking. Alternatively, he could include in his mid-cruise PA that they had been asked to find out the results and hoped to do so if they got a chance.
It's all about
PR and looking after the punters, Notso. Better to spend your time doing that than the Times Crossword. You can keep the pax happy and feeling cared-for AND do the rest of your job entirely competently, professionally and safely
and (with reference to your rather aggressive and rude comments to Rockhound), politely.