Daniel's headline reads that he's convinced his life is "complete and utter shit." He watches Natasha walk away, wishing that he weren't falling in love with her. He thinks that his talk about fate and destiny is stupid, and that Natasha is right: life is made up of coincidences that people think mean something. Really, when you follow up on "destiny," it turns out it's all just silly. The idea of destiny is just a story.
It's worth keeping in mind Daniel and Natasha have still only known each other for mere hours. Per the novel's insistence that scale and time matter, there's still lots of time for this to resolve itself and for Daniel to be able to parse out how fate might work in this situation.