- "Yeah, I figured out it was Morse at about the same time you did. Yay us. Let's keep going."
- "Of course it's Morse. That's why I was just now suggesting that the ants were dashes and the aphids were dots. That suggestion, I suppose, is how you 'discovered' the Morse."
- "Because my self-worth is totally tied in my puzzle-solving ability, I will now convince myself that I knew this puzzle was Morse all along."
From Player A's point of view, he figured it out first. From Player B's point of view, he figured it out first; Player A was just the first to articulate it.
If Player A blurts out "It's Morse!" no sane team takes the next five minutes to work out who did/did not already know the puzzle was Morse. Instead, they're going to pull out their Morse code cheat-sheet and start to work on the next stage of the puzzle.
Afterwards, Player C's chances of capturing how the idea spread through the group... Yeah, basically doomed. That's too bad. And there's a non-trivial chance that Player B will eventually become grumpy as he keeps reading about all of Player A's insights. "Oh, hey, I'd already thought of some of these, where's my credit?"
Finding out how ideas move through a team is darned interesting. Writing about it is interesting, too. My approach is: leave people's names out of it. If someone pipes up with an idea, I tend to say "someone" instead of "Dwight" or whoever. I talk about the strange ways that theories make their way through a van, but usually stay hazy on exactly who was sitting in which van seat. It seems to keep folks from yelling at me about the writeups. YMMV.