Anonymous51, just to confirm...
"If only he had developed a Hypno Flash device that could work on multiple people at one time, then make up a story that everyone would instantly believe, whether it was told directly to them or not, sort of like a shared collection of memories, but from their own point-of-view. Unfortunately, this device didn't work like that. He had to manipulate the minds of people one at a time, face-to-face."
I'm reading from that he can tell multiple people directly the same thing. But he can't let one of them tell it to another and have that work...
So, he's about to tell Zoe and Jon something...and they are both under his influence, and he's standing right here, so they'll both believe him.