Ah, that explains a lot. My suspicion is that had it been the player of the wizard it may not have been the same issue...
Agreed.
I presume this was a 5e reprint of the adventure?
Yes. Puzzles like this are very much about challenging the players, not the characters. The way I'd usually handle them would be to have the party as a group work through the problem, and then assume that the answer came from the most appropriate character, regardless of which player provided it. (Ideally, I'd persuade the players to report their answer through the player of that character, but such things are never perfect...)
That said, my preference for "challenge the players" type puzzles is to avoid outright puzzles, and instead build the puzzles into the dungeon - perhaps there are repeated motifs they can observe and work out, perhaps there's a gap in the map that points to the existence of a secret door, or whatever.
(But, by and large, I do take the view that "challenge the player" puzzles are a valid form of challenge in the game. YMMV, of course - some people prefer all challenges to be character-based.)