See, now maybe I'm off, but I don't think in the book she could have loved Raoul that intensely. She lied to him, and she liked to Erik too, and basically was never honest with anyone. She could have left Paris with Raoul and never did! Instead she was like, "OH BABYBABYBABY THIS DUDE IS SO CRAZY." And then returned to him the next day.
It's sad because all Erik wanted was some affection and he never kissed anyone before. :(