He certainly knew that this "Green-faced Ghost" was someone Yu Hu had hired to impersonate the original, with the purpose of sowing discord between the Green-faced Ghost and Qingyuan Fist Village, and also to make the whole affair seem more plausible.
By portraying the Green-faced Ghost as a member of the Calming Sect, it further explained why the Tiger Saber Gang would take the initiative to confront the Calming Sect.
Because the Green-faced Ghost had previously killed the Tiger Saber Gang's Master, Zhang Mingze, the Tiger Saber Gang's involvement was both a matter of justice and a quest for vengeance.
Moreover, an important point was that the Green-faced Ghost had originally been a member of the Qingyuan Fist Village, and when he killed Zhang Mingze, the Big Leader had even assisted the Green-faced Ghost in the act, with the two having cooperated in the past.
This was solid evidence, confirmed by many.
