Is the addition of a trustworthy narrator accepted unconditionally?

The questioner : Is the addition of a trustworthy narrator accepted unconditionally?

The Shaykh : No, it is accepted only when the narrator who added the detail is equal in trustworthiness to the other narrator who did not include the addition. If they are equal in trustworthiness, then the addition is accepted. However, if the one who added the detail is more trustworthy and has better memory than the one who did not include it, then the addition is not accepted. Likewise, the addition is not accepted if those who contradict him are more numerous than he is.