If you learn about someone’s old private weakness and publicizing it serves no legitimate purpose, spreading it in gatherings or online may be deeply harmful. Concealment does not mean declaring every wrong action acceptable; kind, private correction may still be appropriate.
However, ongoing abuse, risks to children, serious fraud, or other real harm must not be concealed under the name of protecting dignity. Necessary information may need to reach a responsible adult, qualified authority, or appropriate institution to prevent harm.
Thus سَتَرَهَا should be understood as protecting a person’s legitimate privacy, not enabling injury or injustice.