1. I've read everything, even the post by OP showing CBP phone number that called her.
2. I've also read and understood the baggage transfer.
Now, having a knowledge or two about how scams happen, I won't be surprised that though that number is CBP, it actually wasn't CBP. Yes, there are ways to do that. My own number has called me a few times. So, it wouldn't be hard for someone to use CBP contact of POE to call you. Is this what is called spooking? I don't know.
Anyway, you do know these numbers are public and can easily be found online. Best way to find out is call CBP yourself or go to them at the airport.
My bet is that he's already in US at someone else's house.
You should have booked his ticket yourself and not use a travel agent. The travel agent might be on this too. Had you booked it yourself, you would have had better information if he indeed did board or not.
How old are you two? @Shelldb