@givemersspls It's pretty straight forward
[ul]Yang Kai can kill during a sparring match with no consequences.
Zhuang says "we weren't sparring, he was just trying to kill me for no reason".
The disciplinary member described the punishments for murder outside of sparring will entail
Su Mu's subordinate states that they were sparring, thus the punishment doesn't apply
Zhuang and the disciplinary member intimidate the crowd who were witness to the sparring so that they will not speak out to confirm that it was a sparring match.[/ul]
To put it another way, if no one is willing to testify that it was a spar, then Yang Kai gets punished as a criminal.
Of course the part that wouldn't make sense is that there are a number of people observing the spars of every disciple who would be able to testify as to what happened anyway, so it's pretty pointless to try intimidating a bunch of low ranked disciples anyway. They would have to intimidate the people recording the matches.