[As you had discovered before, Impostors weren't truly flawless. While they would possess every memory and be completely identical in appearance and mannerisms to the original, they would still have one flaw that would give them away as the impostor.]
[The problem was that most, if not all, Train Conductors were misled by the World Will to think that it's impossible to figure out which is which and that the Impostors' impersonation ability is perfect.]
[When a Train Conductor attempted to figure out the flaws of an impostor, no matter how stubborn they were, they could only do it for several minutes and would then give up. After all, their preconceived notion that impostors were flawless would linger in their mind, making them feel it was pointless to keep trying to expose the impostor.]
[But, as your Hint Prompt had proved, they weren't flawless and had one glaring flaw that, even if they could logically answer or prove that they could do it, they couldn't perform it when asked.]
