Originally Posted by Renall
There is somewhat of a bigger problem with the Shkanon considering that situation. Erika went about it in a roundabout manner but ultimately Shkanon would've been too easy to figure out for her. She was searching how Kanon could be in the next room over. She guessed there was something wrong with names. At that point it wouldn't have been much at all to say Someone in the next room over have more then one name, one of these names is Kanon
basically what Battler said about Kinzo in arc 4... That would've been game over for the witch's side. Both room are as "open" as each other : One has a window seal's condition being unknown while the other has a hole in the time-sequence of the red allowing anyone/everyone to leave it before Erika sealed it.
From a trick, mistake, lure, taunt, trap
POV, it's far more intelligent to leave something so open as the window's seal, ensuring that Erika would make her theories about it. Assuming Shkanon is false, then Beatrice had no problem. Anything Erika would say about the next room over or the people in it, she could deny it endlessly. This would make victory not simply something that hinges on Erika's formulation of her theory, but instead something somewhat certain.