As a former structural engineer and regarding ‘The Breach’ diorama, I find it hard to believe that the scrap of wall remaining between the roof of the ‘breach’ and the window above would remain in place for very long once the beam over the original opening had been destroyed.
That being said I could be overthinking it a bit, and old brickwork is quite/relatively pliable if it used lime cement and might therefore have settled into a self supporting ‘form of arch’.