Our attempts to learn are stymied by the simple fact that we could be correctly following the evidence to A, up until the moment that suddenly it's actually B, and anything which validly pointed to A before is now an invalid false clue.
So .... it's exactly like every episode of
Castle or
House M.D. or
CSI or
Law and Order, or .......
Not exactly seeing the conflict here. If detectives are following Theory A because that's the evidence they have, then suddenly they're faced with evidence that changes everything to point to Theory B ..... ?
Look, I'm not saying that there isn't some specific quantitative difference between "100% pre authored mystery solely created by the hand of the all-wise GM to amaze and entertain" and the "90% pre-authored mystery, but 10% left open to follow emerging drama, character stakes, and thematic impact". Could it impact play? Possibly, if you're playing with a certain type of player who demands fully that the procedural operation of play meet their own prescriptive need to only approach a "mystery investigation" as a "real life investigator would" (despite the fact that the investigation itself is a fictional construct wholly created by another fallible human and will likely have inconsistencies and holes because the author of the fictional construct doesn't write procedural crime novels for a living).
If you're playing with my players, all of the hand-wringing, word-parsing over "Oh my gosh, is it actually mystery????", the overbearing one-true-way-ism about how "If you change anything now, it will be terrible for the players, they'll hate it, it will ruin their enjoyment of the game, it will be this phony, fake, transparently hollow gameplay experience" is so wildly overblown and the 180-degree opposite of my own personal experience that it's actually quite depressing.
I don't want any new GM out there to get caught thinking that just because he or she came up with a super-cool idea six months ago for a "mystery to solve", but now they see a way to ACTIVELY ACCELERATE the fun and enjoyment of their game, that they're somehow now trapped---lock, key, and chain---because "changing the mystery now" is THE ULTIMATE BADWRONG EVIL and they should never do it.
I've played and am actively playing in games RIGHT NOW that completely blow that theory out of the water, and the players are having a great time, and actually ENJOY filling in the margins of the 10% left open.
Now, if your group is totally programmed to live, breathe, and eat the "trad value system of RPG play," then yeah; do the "100% pre-authored mystery" instead of the "90/10 mystery". It's no skin off my back. Just don't deny your players better gameplay experiences just because of the dogma.
So...you're now literally admitting that the thing you're talking about interferes with "solve a mystery".
Why, exactly, are we arguing if you are outright admitting the thing I've been aiming at this whole time?
I think I just answered that question above.