After Fiona jumps from the train, Ruby and Billy spend several seconds debating whether to jump. Yet when they do jump from the train, Fiona is directly parallel from where they landed.
In the book pitch video, Billy says that after texting "run" that he and Ruby are supposed to meet at "Grand Central Station". While often referred to as "Grand Central Station", the iconic New York city transportation hub is actually named "Grand Central Terminal" because it is an end point for various train lines. A station would be one stop along the line.