At first thought, I was pondering how anyone could miss something as simple as a gorrila walking through the middle of the screen. Then I finished watching the video.
I completely missed the curtain changing color and the girl leaving.
Seen one of these kind of things before, but I didn't expect the gorilla. I got the passes right both times, saw the gorilla both times, and saw the curtain change color. Didn't see the person leave, but I was suspicious of it.