What is the grammatical and evidentiary force of «اتُّهِمَ»?

Al-Ḥārith al-Aʿwar: Narrator Criticism, Variant Reports and Evidence

• Al-Ḥārith made a confession
• Ibrāhīm vindicated al-Ḥārith
• It is passive: al-Ḥārith was accused
• Manṣūr and al-Mughīrah are two names for one transmitter