Woman in Barnes + Noble near the end of the film (spoilers)

I had a real problem with the scene near the end where the woman comes up to Neale and tells him the story of her dead adopted son. I didn't like Neale's response to her about, "Your son died to keep your promise, his real mother died a few years ago, and your son died so he could meet her."

I just felt so shocked and unsatisfied by that response. The movie was going so well, but this moment totally ruined the film for me. I felt so cheated.

First of all, I thought that was a bad reason for her son to die, if that were really the case. Secondly, how does Neale know that the biological mother died?

I think the movie would have been so much better if Neale had simply given the woman a different way of viewing her son's death instead of just giving her an "excuse." Or, this scene should never have been in the movie in the first place.

I don't know how much of the movie is fact and how much of it is fiction, but if that scene with the woman with the dead adopted son really happened, I suppose that's reason enough to keep it in the film.