Nalan Shuo and the others were aware of Tong Han's relationship with him. With Tong Han's testimony, this matter became even more credible, and the Patrol Defense Office would hold the Ghost Sect accountable, while he just counted as dying in vain.
It's not entirely in vain, as the Jiu Mountain Family would use his death to make a big fuss.
This is merely speculation, but it cannot be denied that the possibility is very high. Another guess is that Jiushan Cangxuan also couldn't confirm what exactly this treasure on him was, so he remained inactive to see his reaction when he realized the Wordless Heavenly Scripture was stolen.
If his reaction was intense anger followed by swallowing this dumb loss, it would indicate normalcy. However, if he fled in sheer panic, it would prove that he had a guilty conscience; otherwise, why would he run without reason? This garment definitely has major issues.
