Nobody is free from sins & faults, except the Prophets of Allaah (peace be upon them). Thus, the concept of "ismah" (absolute reverence) can't be found in any of us. However, trying to always be pure of sins is a must to all of us.
People fall under two groups with regards to sinning:
The first is a person whose situation is concealed & is not known to be committing sins (atleast to what people know).
[Surah an-Noor 24:19].
Here, what is meant is, it is sin to spreading news of
"Strive hard to conceal the faults of sinners, for broadcasting their sins brings shame to the Muslims, & the matters which are most deserving of being concealed are faults."
“Overlook mistakes committed by people of good character”.
This was narrated by Abu Dawood and an-Nasaa’i from the hadith of ‘Aa’ishah (RA).
“Tomorrow go to this woman, O Unays, and if she confesses, then stone her.”
Such a person who sins openly won't be spared by the shariah, the hadd punishment ll be carried out on him, so as to put a stop to his evil & deter others.
If a person is not known to bother people, & it was rather a mistake on his part, then there is nothing wrong with intercession being made for him so long as the matter has not reached the authorities. As for the one who is well-known
This was narrated by Ibn al-Mundhir and others…
Source: Jaami‘ al-‘Uloom wa’l-Hikam (1/341).
Concealment means concealing the fault, but concealment cannot be praiseworthy unless it serves an interest & does not lead to any negative consequences.