He probably should have realized that. He sort of had, a little, in his gut. But at that time, when they'd been coming up with the plan, they'd needed something. Poe had been focused on the task at hand--but more important, he'd trusted Finn. Technically, it had been self-interest that had led Finn to rescue him, but it had been a rescue anyway. Poe had known, looking the man in the eye, that he was worth trusting. That he was a good guy. That he'd figure something out.

So this doesn't change any of what he'd known. And he might as well say so. "I kind of guessed. But I also trusted you to figure it out. You're solid."

That's right, Finn's only just woken up. This isn't old news to him. "The charges General Solo and Chewbacca planted put a big hole in the oscillator. Big enough for me to fly my X-wing in and blow it all to hell while you and Rey were dealing with Kylo Ren. Chewbacca picked the two of you up when the planet started to collapse and we escorted the Falcon home."