فَحَصَ الْأَمِينُ النُّسَخَ بِدِقَّةٍ.
The custodian inspected the copies carefully.
فَحَصَ الْأَمِينُ النُّسَخَ بِدِقَّةٍ، وَلَمْ يُتْلِفْ شَيْئًا مِنْهَا.
He inspected them carefully and did not damage any of them.
“Bi-diqqatin” adds a useful circumstance about the manner of inspection and may serve a tatmīm function in context. The further clause “wa-lam yutlif...” can guard against the suspicion that handling the copies caused harm, thereby functioning as iḥtirās.
The first type of addition enriches the account; the second specifically prevents an unintended inference. The two functions can coexist.