Logic:
Is this a case of non-monotonic inference?
Owing to the lack of epistemic access into Hui, the complete absence of disagreement is difficult to distinguish from stupidity. Those that disagree on some things but not all. In their lack of disagreement on some fronts is proof that they are in agreement not blindly opposed, and disagreement in some shows they have been thinking/engaging about the things enough to form a different, if albeit, flawed opinion
However, Hui unlike the stupid also lives as per the teachings meaning the agreement is a result of the endogenisation of the teachings
Non-monotonicity: The agreement on all fronts alone make the inference to stupidity permissible in a way that one who agrees on most but disagrees on some is inferably non-stupid
The addition of new information- the way Hui behaves alters the direction of conclusion. The inference to stupidity is no longer justified. Rather this new information means that Yan Hui has taken the instruction to hear better than those that disagree because he has seen why the instruction was right to begin with