Well the NBA doesn't have any jurisdiction over the companies. They could ban them from any future deals with teams but I assume that's already a given. Anything else would be on the legal system.
As for Leonard, he's allowed to take as much money as he can make as outside income. He wasn't breaking any league rules, the team was. Even if he was not innocent of what was it really meant.
So, he's paying the league back $700,000. Is that allegedly the amount of money that actually violated the cap or is it that number for some other reason? And why is it paying the league "back."?
A good punishment for Kawhi would be to make him stay with the Clippers, however.