Prophet trusts Bernard more than himself—and the two have never lied to each other, not even once, no matter how helpful or white it could've been. And so, when he told him that Riley wasn't Darkday, that was that. He removed the thought from his mind and just completely chalked it up to a weird, highly coincidental coincidence.
There was also the chance that Riley truly was Darkday, and that Bernard just didn't know.
But the chance of Bernard not knowing something was lower than a meteorite landing on top of his head right now.
But of course, it was also never zero. What if, just what if…
Riley was truly Darkday, and Bernard just didn't know?
Because Lisa tripping out of nowhere while she was handing Bernard coffee was… a little weird. But then again, if he was going to say that Riley tripped her using telekinesis, why didn't he just suspect Lisa of also being Darkday?
Riley was also helping Diana when it happened, and he hasn't even once glanced in their direction.