Not seeing through something and not seeing it at all are indeed two different matters.
The former is when it's visible, but not understood; the latter is not noticing it at all.
In that case, Yuchi directly brought Chen Guangsheng into the spotlight.
He said:
"Recently, I learned from a senior within the Celestial Capital Department about some possible shortcomings within the Demon-slaying Bureau."
"That senior mentioned the Demon-slaying Bureau might stage events, releasing demons themselves to train using the common people."
"In the end, they use the people's deaths to earn accomplishments and bolster their justified existence in this world."
Yuchi did not mention Chen Guangsheng's name; otherwise, if he could betray Chen Guangsheng today, he could betray Xun Yu tomorrow.
Neither Xun Yu nor he liked that, what was that saying again?
Attack issues, not people; that's the strategy experienced officials favor most.