Just doing the math, the odds are overwhelmingly in favor of this being a suicide. That's a pretty boring ending though, a lot of people will reject that just because it's just too dull. Still, Conduit must be such a jerk that she found enough motivation to punish him by offing herself. Her plan worked amazingly well.
Suicidals do not neatly pack their bags and set them by the front door in anticipation of flying home the next day. They do not get on their computer and pay for airline reservations that they know they will never use. They do not call their parents and chatter on excitedly about finally finishing school and getting their degrees.