I’m sorry but this… is just an assumption on your part. R7 later said there was a “trap” planted in EP5 and he was pretty clearly referring to this part, which ended up fooling a lot of people. Something which he couldn’t have done if he went with your idea. He set out to trick the reader the same way Erika would end up being tricked, while at the same time demonstrating through the game itself how that trick came to be. Assuming there was another reason for it… an assumption, not proof. The phrase “everyone is here” doesn’t in itself proof that Erika was saying in absolute truth “ah yes everyone is here”.
Once again… an assumptions. The ShKanon solution applied here isn’t nonsense. It’s, in fact, the direct result of understanding how the mechanics of Beatrice’s magic can be used to twist what we perceive as reality and fatasy in the games.
And besides, Lambda’s lines are more or less what I would’ve thrown out as a means of distracting the players, being in a GM position a few times myself. What else would she have said, exactly? “Aw, shoot, golly don’t go down that route”? Given her character, acting cocky until the end and taunting the player isn’t something I’d take as proof.
You’re applying the Knox in terms of meta-reasoning. As far as the events on the board are concerned, objectively - Erika’s fake solution, nor any other for that matter, would’ve relied on Erika miscounting.
Not to mention, that Knox relies on the detective accidentally finding a way to the truth or solution, not making an accidental mistake that diverted them from the truth.
The last part especially is just enforcing rules that were never set in place to begin with, sorry. Human mistakes are human mistakes. All mysteries can have them, even the detective can make them. In fact, numerous times in detective fiction the detective does, in fact, make a mistake - either as a result of being deceived, misinterpreting a clue or just being flat-out wrong.
Fake blood and Nanjo and others simply lying, Erika buying into the lies because she’s a teenager and novel freak who, again, made a mistaske. Her position as a detective in the meta doesn’t make her infalliable. It just means what you see through her lens and her lens alone is GURANTEED 100% to be what is actually happening. It’s the exact same way Battler was in the first four games.