The main text illustrates this with «ما يعلمه الحكيم فهو يعمل ما يعلمه», in which the antecedent of a pronoun affects what is being asserted and whether it is true.
A pronoun may appear to refer to the nearest word, while context points elsewhere. If an argument silently assigns it different antecedents in different places, it no longer preserves the original claim.
The practical repair is to replace the pronoun with its proposed explicit antecedent and read the proposition again. This reveals which judgment each reading entails.