This is actually the best scenario. In a sense that everything will cu... i mean, come together inevitably: Yuri got out to see Reiji and is bringing the chekhov gun that can free her from the clutch if the abyss Reiji dragged her into. Ishibashi may be already on his way to pick Reiji and possibly realize he isn't in his house, setting the alarms.
Nagi's backstory pretty much will end with Reiji, having total awareness, pulling a last counter question that can be interpreted as an indirect confession. Something along the lines of What if you can still be loved despite of everything?? If a person who can show you that love appears in front of you appears, what will you do?, something enough to make Nagi reflect on her decisions and right when Yuri spots them at the bridge. Inevitably drama and a physical catfight will ensue, but Reiji, as a person who, at his wits' end or when Nagi is in danger, pulls very reckless stunts (like when he stabbed himself as an allegedly final fuck you to his mom and when he escaped from hospital), pretty much he will act on his feelings, but also because of guilt for having pulled Yuri to his own abyss and having tried to kill himself with Chako, he will pull a goodbye confession, and throw himself to the river as a way to expy himself, free Yuri from his abyss' clutch and prove Nagi he also can decide to leave everything behind without an angel of death. That will be the moment Ishibashi interferes, saves Reiji, but also, due to the dangerous stunt, he'll have to put him under custody because Reiji will have to answer some difficult questions.
That shit will also imply Reiji may finally see Gen and have a last talk.
Seriously, this pretty much was the best thing that could have happened.