During the take in the morgue, when Moser and Dr. Leo Graf examine the corpse, in the face close-up, its eyelashes make slight nervous moves.
When Dr. Graf is discussing his preliminary findings to Moser, he expresses doubts as to Mrs. Mader's suicide judging by a second set of ligature marks on her neck. As Moser inspects them, we see a close-up of her neck with the bruising he mentioned as well as her pulse beating strongly under the skin.
When inspector Moser talks for the first time with the Riedl couple, a few centimeters of the boom mic quite obviously enter the screen. The mic being black and the wall being beige, it does hit the eye.