Imperial Tutor was very clear that the self-destruction mechanism in the Royal Treasury was an extremely top-secret information and it wasn't until the demise of the entire country before it would be activated.
So the only person who knew how to activate the self-destruction mechanism was the Emperor.
Even the Crown Prince was not qualified to get associated with this top-secret information so naturally Imperial Tutor did not know any better.
But now, this mechanism had suddenly been activated!
How did Huang Yueli get to know of this top-secret? How could she possibly activate the self-destruction mechanism? Surely it could not been told to her by the Emperor personally right? No, this was impossible…..
Or could it be that the Emperor had already decided to leave the position of Crown Prince to Prince Yu Wang so he conveyed the top-secret information to him and Prince Yu Wang let the information out to Huang Yueli?