Revealing mistake: In the shot of the helicopter hovering above the apartment building, the blue screen technique is needlessly revealed by the eratic and physically impossible movements of the chopper. This could have been avoided if the camera shooting the aircraft had been stationary. It appears, however, that it was a handheld shot.
Revealing mistake: At the end of the movie, when Jimmy Stewart is hanging in the window, we can see that it's a stunt double.
Chosen answer: I think her head was in the hat box after he dug it up from the garden where the dog was digging under the marigolds.
You are correct that it was her head.
raywest ★