the movie was certainly based on the song (as was Harper Valley P.T.A. the hideous follow up smash). The whole question of who threw what off the bridge was a mild obsession of the time. I remember that Bobbie G. gave an interview for Life (?) magazine where she said that there was more money in mystery than in spelling it out. This obviously doesn't seem to have stopped the moviemakers. Two of the lines missing are: "Chile, what's happened to your appetite, I've been cooking all morning and you haven't touched a single bite."