While the Deputy D.A. delivers a fiery closing argument in Louise Selff's preliminary hearing, Louise's friend, Rosemary Welch, is actually smiling. Under the circumstances, this is so far out of character as to constitute a serious lapse of judgment by the director.
After Glenn Arcott demonstrates his process to Paul Drake and attempts to show that the bricks have been bonded, when he moves the bricks it is obvious that they come apart.