Wishbone: Like that makes any sense. "Oh, he repeatedly refuses to talk to me, even though I was explicitly told that he would. Maybe if I go wait a while at a camp fire, he'll change his mind". What the hell kind of logic is that?
F4LL0UT: It's not specifically about using the camp fire, characters can get pissed at you and it just takes time until they are willing to talk to you again. I instantly understood that logic the first time I played the game and even thought that it's a nice realistic touch. And that rule is true for a whole bunch of dialogue options with various characters throughout the game, it's not some obscure gamey logic in one specific situation.
Also I'm not sure you even need to talk to him to proceed, at the very least there should have been various other paths you could pursue in the meantime. The Witcher generally isn't structured like your average RPG where progress is all about checking stuff off a list, it's quite organic design, you will inevitably block some paths and ruin relationships and in my experience the game ALWAYS offers you an alternate option. I've been in some serious cluster fuck situations in the game which I would have assumed were game breaking bugs in almost any other RPG but the designers had anticipated and prepared for here. There may still be some bugs in the game but none of the remaining ones are game breaking in my experience.
Well, I tried speaking to absolutely everyone, and the only one who had anything worthwhile to say was the priest, although "worthwhile" is a relative term in this case, given that what he said turned out not to be true.
Also, given that the progress apparently relies on a mechanic not found in any other RPG, and not found at any earlier point in the game, and there is no mention of it at any point leading up to that, I'm afraid I'll have to stick to my "piss-poor game design" assessment.
Kudos for "instantly understanding that logic", but to me, when an NPC keeps repeating the same line over and over, that is the universal signal for "you're not getting anything more out of him". If you make a game where an NPC can repeat himself over and over, and
then suddenly change his mind, you need to make damned sure you inform the player of this, because it is
not intuitive.