The one who died couldn't have been emissary song bu, because he had enough time to escape. There was no reason for him to sit at home and wait for death.
It was unlikely that the dream wizard would kill him because it was not to the point where he needed to do so. There was enough time to retreat, so there was no need to go to the extreme.
Then why did he have to fake a suicide to escape punishment?
Xu Qi 'an had two speculations, one was that envoy song was also a scapegoat, and killing him was equivalent to cutting off all clues. At the same time, they fabricated the false story of her committing suicide to confuse Governor Zhang.
Second, envoy song bu was stalling for time.
When they were discussing the case earlier, Xu Qi 'an, Governor Zhang, and the others had come to a consensus that if they forced the other party into a corner, there would definitely be a bloodbath.