This situation is of no concern to the Imperial Guard.
What exactly does The Imperial Guard protect within the Terra Imperial Palace? No one knows, but it isn't the High Lords, let alone ordinary Empire officials.
But who was responsible for turning the assassination against Gu Hang into a forceful killing?
The initial bullet did conform to the definition of an assassination. A sniper, hidden in the shadows, fired a silent and deadly bullet. If it had been successful, Gu Hang would have ended up like the countless Empire officials who had died within the Terra Imperial Palace that covered the entire Tibetan Plateau. Whatever storms the future would bring, it would no longer be the concern of the dead.
But that bullet did not succeed, nor did the second one that destroyed the entire limousine, neither did the four waiting experts.
The commotion was getting bigger and bigger.