Even if the Wang Family strictly manages their own industries and keeps their accounts meticulously, what about those joint ventures established with their in-laws?
From the Shouda Trading Company, to the Changning United Manufacturing Department, to the Qingluo Development Headquarters, and so on, the Wang Family and their in-laws have established quite a few industries together. Members of the in-law families hold positions in each of these ventures, and it's clear that the Wang Family cannot manage them as strictly as they do their own clan.
Such joint ventures have always been hotspots for tax evasion. As long as one investigates them casually, issues are bound to be found.
At that point, they could simply report it, and the credit would be as good as picked up for free.
