By now the themes of obsessiveness, the nature of personal identity,
amour fou, etc. are a little bit threadbare they've been put forward so
often. Not that they aren't an important part of the movie, but they've
become rather obvious and facile. They do all take place against the
background of Elster's murder plot, and the one adds to the other and
makes a fine combination. I don't know if Vertigo is a masterpiece or
not, but it is a very interesting movie.
For about the fifth time, if Elster just threw his wife off the tower, he would
be an immediate suspect. He went through the whole charade with Madeleine
being followed around by Scotty to establish her suicidal tendencies, and
his plan worked like a charm. Why didn't he then bump off Madeleine? That
would have been another corpse to account for and if he was ever connected
with her that would have been bad news for Gavin. So he took the risk that in
a city of 750,000 people Jimmy wouldn't bump into the refitted Kim Novak.
The only flaw was that he was operating in a movie, not in real life.