"Most of the people here have no idea what Pokemon are, and I trust them on that. It's hard to imagine a world without Pokemon, I know, but...." But it's that, or call them liars, or tell them they can't trust their memories. For the sake of giving these people the benefit of the doubt, he'll accept the multiple worlds theory for now. If he gets evidence contradicting it, well, he can always change his mind later.

"Nor am I. But we can worry about that if it comes up -- right now about all we can do is investigate this place." The possibility that there might not be a way home, that whatever brought them here is one-way and they're stuck here for the rest of their lives, does occur to him, but he'll keep that one under his hat for now.