Agreed. That is Sterling's best argument.
I would consult a top lawyer
I'm sure he's already consulting several.
on the theory that the penalty is out of proportion to the wrong. There was a 1993 case involving punitive damages or a penalty that the court, If I remember correctly said was wrong.
The punitive damages cases are probably not going to help him here; the $2.5 million penalty is an amount specifically authorized by the NBA Constitution, and the ban on owning the team is arguably not a financial penalty at all, because he can sell it for a hefty profit. Sterling may well litigate this, but I doubt he will do any better than George Steinbrenner did when he sued to overturn the Commissioner of Baseball.