Is this rule correct: If the one who conceals defects (mudallis) is frequent in narrating from his shaykh, then his "ana'ana" is accepted?

The questioner : What is the validity of this rule: If the one who conceals defects (mudallis) is frequent in narrating from his shaykh, then his "ana'ana" is accepted?

The Shaykh : This is not sufficient. Rather, one should observe whether he is frequent in narrating from his shaykh; was he known for frequently concealing defects from him? If so... regarding this rule. However, if he is frequent in narrating from him and rare in concealing defects from him, then the rule is in its proper place.

The questioner : May Allah reward you with good.

The Shaykh : And beware of that.