Tony,
Both of you got a low mark for CRM, but in a very different way. On the return flight, when you challenged him again about figuring out Max Alt you could accept, I would not have liked it either. You should have pretended nothing happened the day before, totally ignored him until he had finished with the QRH.
And for him to reply "I'm the captain, I make the decision, YOU'LL HAVE TO TRUST ME' is very weak on his behalf. Meaning: Rule #1, I am the captain, I am always right, rule #2 if in doubt go back to rule #1. You sure know better then him for picking a good cruising altitude and probably more.
Why going to FL410 when 370 was available is beyond comprehension. He had the chance to end the flight at altitude very close to Optimum Alt and he picked the worst one actually. Even FL310 would have giving pretty much the same fuel flow than FL410 if flown at LRC, but a slightly lower TAS, I admit. What increases fuel burn as well when flying near Max Alt and it's not perfectly smooth, is that A/T are really working hard, moving back and forth trying to maintain the darn speed and when these throttles are moving all the time, we all know it means so much for fuel economy.
Tony, if that captain has the habit of accepting or requesting altitudes close to Max Alt, he's costing tons of fuel ($$$) to your airline and he stands to be corrected. I noticed that this is a modern times' disease with some pilots to thing that the higher the better. Where they got that from, not from you nor me I guess. Before getting ponded here, sometimes it is justified, self explanatory I think.
The guy who answered your report was either forced to write what he wrote, or he should go back to his books as well. Your airline has put in their SOP how to pick the right altitude, and avoid what happened, by staying within 2000 feet of the Opt Alt for optimum fuel burn and that guy had no reason whatsoever to act otherwise and your are being answered something like: "the captain is at no fault, correct the First Officer". With what happened between the time you reached FL410 and TOD proved you were right.
Next time I suggest you think twice before sending that kind of reports to Ops. Ask an experience guy whom you trust before pressing "send message". Sleep over it a couple of nights and when well rested, with most of the emotions behind you, and some advice, then go ahead.
Good luck and keep up the good work. Some finesse maybe on how you express your concerns to your boss could help, I think.
Ready for the flak, guys.
Cheers!!!