At the end of the film, when Neil puts the nest back on the building, a chunk of the plastic bag is left on the metal hooks of the ledge. When the bird comes back the plastic it is gone, and the nest has miraculously moved from the left side to the middle of the ledge.
In the drama scene where they talk about their Father's suicide, Neal is holding his mother's hand, at the next shot where Paul stands-up Neal is clearly not holding hands with his mother.