In a-lasta tarā an qad atayta bi-muʾayyad, the surface form asks the addressee whether he can see the seriousness of what he has done. The complainant is not waiting for information: he is scolding the addressee.
This is reproachful interrogation. The next question, mādhā tarawn, addresses the assembled group rather than the single offender. The move from an individual challenge to a collective judgment increases the dramatic tension.