Fache is growing impatient with how long Langdon's been in the men's room, but Collet reassures him that if he were onto them, he'd have tried to run.
Collet understands why Fache seems so invested in making this arrest: Fache's recently come under scrutiny for his aggressive tactics and love of high-tech (expensive) equipment. If he could make a high-profile arrest using those methods successfully he stands a better chance of holding his position long enough to retire with a pretty lucrative pension.
Uh-oh. The cryptology department calls for Fache. It's something about Agent Neveu…and it's not good.