money, and the NIL guys can't write their contracts in such a way that says, "you only get this if you play for UNLV," meaning they aren't giving you a contract until after you've arrived on campus.
The response from UNLV, hiding behind the fact that they aren't legally responsible for anything an assistant coach said, leads me to believe the kid's version is accurate. He was promised $100K and they were only going to make good on $12K. Absolutely the kid should walk.