At 1:12:27 into the movie, as the camera pans to Gavin on the ledge talking to Hollis, the sun is high casting only a partial shadow ton the gray building in the background. The camera then switches to just Hollis looking out of the window, and when it goes back to show Gavin again, the shadow on the gray building behind him covers it almost completely. But the next two times we see Gavin at the same spot the shadow moves back and forth, revealing that the scenes were shot earlier but cut in for the sake of the narrative.
the scene where she is making the bed, he joins in to help. The bottom part of the sheet is not tucked under then all of a sudden it is tucked under and they've not even touched it!.