The problem is that there was a verbal agreement in place, similar to the one DeAndre Jordan broke with the Mavericks a few years back.
A good agent doesn't pull this. If your client comes to you and says, "I change my mind, get me a different deal" you're supposed to say "Tough luck, you agreed to the deal, either sign it or find another agent before you ruin my reputation." Will teams continue to deal with Rich Paul, though? Of course! That organization has its tentacles across the whole league, thanks to the power and influence of Lebron.
This is the fundamental problem with the league. Teams -- especially small-market teams, and even well-run ones like SAS -- have no certainty. Players decide whimsically when and where to play, and in some cases (like Kawhi in his last year with SAS), IF to play. How do you run a team in that environment? The league has a problem and it's not going away any time soon.