I have a bit of a hard time seeing how the lawsuit succeeds. With regard to the $70M contract that Noel Bonzi'd himself on, he took bad advice, but it was his own decision. With regard to his subsequent contracts he didn't receive, it will be difficult to prove that those contracts were below Noel's market value.
But I will say this: if the lawsuit does succeed, it would likely have serious unintended consequences that would be in the favor of NBA teams and to the detriment of NBA players. If agents can be penalized millions of dollars for bad strategic advice, or for negotiating anything less than the best possible contract, then the risk in performing these roles would likely be too great for agents to continue doing them. Players would likely be left to formulate their own free agency strategies and negotiate their own contracts, with agents acting only as legal assistants in reviewing the contracts before signature. Teams would take full advantage of this. And Noel's payday would translate into lower player salaries across the board.